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Sharp Motorsports 4600 Class Early Bronco

'84 Bronco II

El Chingón
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Ever since attending my first King of the Hammers in 2016 I have had a hankering to race in the in the 4600 Stock Class during the Every Man Challenge. After the initial enthusiasm and planning out the costs to put together a reasonable race effort, I had resigned myself to racing being too expensive for an average Joe like me, and decided I should be responsible and used my bank account for a down payment on a house since I was a renter at the time.

Fast forward to 2020, I now have a house and a shop built, and after watching the race this year, my desire to race had been rekindled. Ford's $25,000 stock class contingency that they announced right after KOH was over was just the push I needed being a Ford guy (even though I am under no illusions about my chances of finishing at KOH, much less winning :laughing: ).


So, what Ford should I choose to race? There was a discussion in Chit Chat over at the old place, and this is what I came up with:
'73-'77 Bronco

Pros:
  • 302 available (starting in '69, earlier models had the 289)
  • C4 available (The sole 3 speed manual used through the entire '66-'77 run is a non-starter for racing, and no automatic was available '66-'72)
  • Coil spring solid axle front
  • Short wheel base for the rocks (92")
  • Relatively narrow body(~68")
  • Somewhat lightweight (~3,500-3,900Lbs bone stock W/ V8, steel hardtop, and doors)
Cons:
  • Expensive and hard to find
  • Max 95" wheelbase per 4600 rules is a bit short for the desert and compromised stability on steep climbs
  • Carbureted stock, so additional effort/expense converting to fuel injection

'86-'90 Bronco II

Pros:
  • Cheap and plentiful
  • TTB would be good for desert sections and cheaper to build than an SLA IFS, yet still decent in the rocks
  • 2.9L is fuel injected and makes 25HP & 20LBFT more than the '84-'85 carbureted 2.8L
  • Short wheelbase for the rocks (94")
  • Narrow body (~65")
  • Lightweight (~3,300-3,400Lbs. stock)
Cons:
  • Max 97" wheelbase per 4600 rules is a bit short for the desert and compromised stability on steep climbs
  • A4LD sucks and was the only automatic available from '85-'90 (The C5 available in '84 is basically a C4 with a lock-up converter, but you would be stuck using the 2.8L)
  • The manual transmissions are geared relatively high and aren't particularly stout, but aren't terrible either. The Toyo Kogyo 5 speed ('84-'87) and M5ODR1 ('88-'90) are the better transmissions. The Toyo Kogyo has the lowest first gear, 3.96, vs. 3.72 for the M5ODR1. The Mitsubishi transmissions should be avoided.
'90-'97 Regular Cab Short Bed Ranger

Pros:
  • Cheap and plentiful
  • TTB would be good for desert sections and cheaper to build than an SLA IFS, yet still decent in the rocks
  • 4.0L OHV available during '90-'97, which is a significant upgrade over the 2.9L or 3.0L V6s.
  • Wheelbase (107.9") is a decent compromise for desert, climbing stability, and crawling through the boulders
  • Narrow body (~65" '90-92, ~68" '93-'97)
  • Lightweight (~3,300-3,500Lbs. stock)
Cons:
  • Not a great departure angle and worse break over angle than an early Bronco or Bronco II
  • A4LD sucks and was the only automatic available from '90-'94, however the 4R55E used from '95-'97 is better.
  • The M5ODR1 is geared relatively high and isn't particularly stout, but isn't terrible either.
'91-'94 2 Door Explorer

Pros:
  • Cheap and plentiful
  • TTB would be good for desert sections and cheaper to build than an SLA IFS, yet still decent in the rocks
  • All Explorers have the 4.0L OHV V6
  • Wheelbase (102.1") is close to ideal for 4600 class.
  • Somewhat lightweight (~3,600-3,900Lbs. stock)
Cons:
  • On the wide (~70" body) and long (~175") side compared to the early Bronco and Bronco II.
  • A4LD sucks and was the only automatic available.
  • The M5ODR1 is geared relatively high and isn't particularly stout, but isn't terrible either.
The 4 doors extra length and weight is only a detriment in my opinion, but could potentially be competitive as well.


The full size Broncos are definitely worthy of consideration due to their good drivetrain, suspension, and wheelbase configurations, but I think they are too wide and heavy to be very competitive on 35" tires.

I really wanted an Early Bronco, but those are stupid expensive, so I was leaning towards a regular cab short bed Ranger. Despite having wheeled a TTB rig for years, I wasn't too enthused about running a TTB rig, and while the 4.0L should be competitive in the stock class, I really wanted the effortless power of a V8. As luck would have it, I was browsing ClassicBroncos.com and ran across a post from a local guy advertising a "fire sale" of his Bronco collection. I met up with the guy even though I had doubts I could afford an early Bronco even at "fire sale" prices, but he ended up being a super cool dude and had a '73 and a '75 in pretty rough shape. He wouldn't name a price for anything and was being coy even when I asked him for a ballpark of what he was looking to get. He told me he would accept any "reasonable offer," so I made him an offer for both the '73 and '75 as a package deal that I was really worried might insult him. He ended up accepting without any haggling to my surprise and threw in a bunch of spare parts to boot :grinpimp: He even busted his ass helping me load them up since they both were non-runners and were on rotten tires!


Here's a picture of the rigs when I got them home back in March (The camo '73 on the left is the one I will be racing):

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Now, I hate to beg like a hooker, but sponsors want social media presence, and I am intending to get me some, so please Like/follow/share the build on Social Media as well!

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More updates to follow shortly...
 
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Originally I was hoping for 2021, but life kind of got in the way this year. Planning for sure KOH 2022, but if I finish it early enough, I might try to hit some of the Western series races. I definitely want enough time to do some shakedown testing before KOH.
 
Cliff notes on the 4600 class restrictions? Looks like from the above lists when making your choice, your limited to stock motor,trans and suspension design any other big limits?

Edit: Disregard, I got the Ultra4 website rules to work.
 
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The '73 is a 302 3 speed manual with a T-shift Dana 20 and a big-bearing 9". After getting it home I realized that it had an ARB in the front and a Detroit in the rear with Currie axles and a 3" lift. It also has fiberglass fenders. The '75 has a C4 that I will be running in the '73 since the 3 speed manual that came in Early Broncos is junk.

For axles, I had three options already on hand:
  1. The Dana 44 and 9" already in the '73
  2. The '79 F250 HP 8 lug Dana 44 and full float Dana 60 in my beater Bronco II crawler
  3. '07 Superduty Dana 60 and Sterling 10.5
The first option obviously is already in the truck and they have lockers, but the track width is too narrow (~58"), the Dana 44 is low pinion (not much droop before driveshaft bind in an EB), they are currently geared to ~3.50:1, and both axles are drum brake as well. The 9" has a really low pinion compared to other axles (2.25" below centerline), and being limited to 35" tires I am worried about driveshaft clearance in the rocks.

The third option I felt was overkill on 35" tires even in a racing environment. They seem like too much of a weight and clearance penalty and would require 17" wheels with the stock brake setups. While plenty of people run 35" tires with 17" wheels, I want to maintain as much sidewall as possible.

I decided to go with the second option since I think the HP Dana 44 front and full float Dana 60 should provide adequate strength for 35" tires without losing too much clearance or adding unnecessary unsprung weight. The HP Dana 44 will get my front driveshaft 3" higher than the current LP Dana 44, and the Dana 60 will get my rear driveshaft 1.125" higher than the 9". These axles are also about 10" wider than the factory Bronco axles, which will help a lot with stability and keeping the body off the rocks. Both axles are welded with 4.10 gears, and the HP Dana 44 has the dual piston disc brakes and flat top knuckles for high-steering. I will need to do something about the welded diff in the front, and plan on running 4340 axle shafts, but I am hoping I can get away with the 4.10 gears for now.

For the engine, I'll be running an Explorer 5.0L (GT40P heads, GT40 EFI intake, and EEC-V (OBDII) distributorless ignition) and just plan to do headers and a cam this season, which should get me up near 300 HP at the crank and be more than most people running in the stock class.

I am planning to rebuild the C4 with a ~500HP kit, run the biggest tranny cooler I can package, and put in a fairly low stall converter (thinking maybe the F41TOW converter from Hughes). I am also toying with the idea of rebuilding with with a low gear kit to drop 1st and 2nd from 2.46 and 1.46 to 2.9 and 1.6 respectively, but I am not sure it is worth the cost for the first season.

I plan to run a Dana 20, but I haven't completely made up my mind yet about whether to run an integrated doubler or a low gear set. Regardless, the output shaft will need to be upgraded and I plan on doing a twin stick conversion as well so I can do digs.

I am going to do a 3-link on the front, and the rear must remain leaves. I am planning on using all of the allowed 3" wheelbase deviation to stretch to 95" (1" front, 2" rear notionally). For steering, I am planning on running a small double ended ram as an assist with a 4x4x2 box.
 
Cliff notes on the 4600 class restrictions? Looks like from the above lists when making your choice, your limited to stock motor,trans and suspension design any other big limits?

Edit: Disregard, I got the Ultra4 website rules to work.

That's pretty well the gist of it, but I'll go ahead and lay them out for others who may not be up to speed:

Engine
You must use the stock engine block that was available for that make/model/year. No forced induction is permitted unless it was originally equipped. Heads, cams, stroker kits, etc. are all legal though. Propane conversions are legal as well.​



Transmission
Basically the same rules as the engine. Must have been available for that make/model/year, but all mods are acceptable.​



Transfercase
Any transfercase is legal.


Axles
Any axles are legal, but they must be the same "style" as what was stock, i.e. solid stays solid, TTB stays TTB, SLA stays SLA.​



Suspension
Must remain original "style", i.e. leaves stay leaves, coil and links stay coils and links, and independent stays independent. Maximum 2.5" diameter 14" travel non-bypass shocks, one per wheel unless factory equipped with dual shocks.​




Body
Outer fenders may only be cut to provide tire clearance, inner fenders must be unmodified. Rockers can be cut/modified for the sole purpose of adding reinforcement. The body may only otherwise be cut/modified to provide passthroughs for shifting linkage and roll cage tubes. Fiberglass/tube front fenders are legal.​



Tires
35" diameter maximum and must be DOT non-stickies.​



Here is the rule book for anyone that wants to take a deeper dive: Ultra4 Rules
 
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After getting the Bronco home, I was excited to get it running to be able to drive it around a bit while I was collecting parts and finishing up my shop. It turns out it really didn't need much, so I am not sure why it spent the last 6 years just sitting in a field :confused:

I rebuilt the carb with a kit I already had in my garage, installed a new fuel pump and battery, soaked the cylinders with a little ATF, and did an oil change and tune-up (plugs, wires, cap, an rotor) and the thing fired right up with some fresh gas.

It smokes a little, but seems to run pretty damn hard for a smog-era 2bbl 302. I think it has a bit of a cam in it since the idles a little lopey and only pulls 13-13.5 inHg (15 inHg is about as much as anything pulls up here at 7,000' though).

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How about going 5 lug on the d44 and full width 9" in the back? Shave some weight, unsprung and rotating mass

I never got the chance to wheel my big eb after my full width d44/9" swap, but it handled unbelievable on the street

shaved a bunch off the 9" too

I pretty much cloned my buddies rig, his worked very well offroad.
 
Heres my old beater Bronco II getting sacrificed for the race effort:

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Front axle out

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Almost fully gutted

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And the race Bronco extracting the carcass

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Off to the Bronco II garage in the sky; I got $72 for the shell :laughing:

 
How about going 5 lug on the d44 and full width 9" in the back? Shave some weight, unsprung and rotating mass

I never got the chance to wheel my big eb after my full width d44/9" swap, but it handled unbelievable on the street

shaved a bunch off the 9" too

I pretty much cloned my buddies rig, his worked very well offroad.

That wouldn't be a bad option either, but I didn't have a full-width 9", and they are getting harder to come by these days. Of course you can buy all the parts to build one aftermarket, but that gets expensive in a hurry. My biggest reservation with the 9" is how low the pinion is. It makes the rear driveshaft more vulnerable in the rocks, and with a stockish wheelbase EB, it is hard to get a lot of droop without binding the driveshafts.

I know the 8 lug stuff is heavy, but I have also read a lot of horror stories from the guys over at ClassicBroncos.com that race in the NORRA series breaking wheel studs and wheels with the stock 5 on 5.5" bolt pattern. It would be nice to run 15" aluminum wheels though. I looked into converting the front brakes on my 44 to chevy brakes, but all the 15" 8 lug wheels I could find were steel.
 
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Before tearing down The Bronco, I wanted to get a baseline weight and CG height. The roll cage tubing size is determined by the rig's overall weight per the Ultra4 rules and I wanted to make a better educated guess on my CG height for designing my 3 link geometry. I started looking at corner scales, and good god they're expensive :eek: Fortunately I have a buddy at work who used to be into auto-cross and had some old school hydraulic corner scales. They are kind of neat; the cylinder area is exactly 1in[SUP]2 [/SUP] so the pressure reading is also the weight.

Here are what the scales look like:

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Getting the corner weights:

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To get the CG height, I raised the front end as high as I could with the jack stands I had, and used the change in weight on the rear axle (65 Lbs.) along with the difference in hub height (7 21/32") to calculate it.

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I ended up with a CG height of 18.15" above the axle center line, so 31.65" above ground level when you add the 13.5" rolling radius of the tires (235/75R15s). For a sanity check, I calculated the static tipping point angle for it to go over backwards and came up with 70.64º, so the CG height seems reasonable. The weight distribution came out to 56.2% front and 43.8% rear.

Pretty nose heavy for the desert, but I frankly am not sure what kind of weigh distribution would be ideal for KOH. I know a slight rearward bias is ideal for desert racing, and a front bias is preferable for crawling, so maybe shoot for 50/50? :confused:


Anyone want to take a guess at what it weighs as pictured? :D
 
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Torreador Ranger was the closest, It came out to 3,330Lbs.

Doing some really rough ballpark estimates for weight I am going to add, I am thinking maybe around 4,200Lbs race weight. 1.75 OD tube is permissible for vehicle weights up to 4,400Lbs, but I think I might be cutting that close, so I might just step up to 2" tube so I don't have to stress as much whether I'll be over weight or not.
 
I would definitely go for 2" tube... our race LJ was ~5140lbs at KOH 2014, which is the last Ultra4 race we did. We built and tech'd on the 2012 rules when 1 3/4" was allowed. This would also potentially allow you to use your rig under more restrictive rules of other sanctioning bodies. We eventually got the weight down to 4900, but getting down to 4400 lbs, for us, would have required serious $$$$$. One part of racing costs some people don't think about is reliability. My rig was a little heavier, but we didn't break a lot of axle and suspension parts. When we did roll, the vehicle was fine. If you reduce a lot of weight, you may be sacrificing reliability, which also becomes an expense of time and money between events.
 
I would definitely go for 2" tube... our race LJ was ~5140lbs at KOH 2014, which is the last Ultra4 race we did. We built and tech'd on the 2012 rules when 1 3/4" was allowed. This would also potentially allow you to use your rig under more restrictive rules of other sanctioning bodies. We eventually got the weight down to 4900, but getting down to 4400 lbs, for us, would have required serious $$$$$. One part of racing costs some people don't think about is reliability. My rig was a little heavier, but we didn't break a lot of axle and suspension parts. When we did roll, the vehicle was fine. If you reduce a lot of weight, you may be sacrificing reliability, which also becomes an expense of time and money between events.

Running a 60 front and 14 bolt rear with copious amounts of body armor I assume? Sounds like you added about 1,300-1,400 Lbs. over a stock LJ vs. the 870 Lbs. I am guesstimating for my build. I am certainly of the mindset that light weight is the way to go and have no intentions of armor plating the entire body, but I understand what you are saying about under-building in places where you might just be shooting yourself in the foot. I was already leaning toward 2" tube for the cage for the reasons you have mentioned. There is only a ~.3 Lb/ft weight difference between 1.75" and 2" OD .120" wall tube, so assuming 100' of tube for the cage and bracing, that is a ~30Lb difference. Not insignificant, but probably worth the penalty.
 
I agree, go with 2", it's safer and aesthetically, it looks better on an early bronco as well.

I've been thinking about your 3 link front VS a radius arm setup and I'm still not convinced a 3 link is a better option over extended radius arms.
The simplicity of radius arms is pretty great, with a 3 link you have the added cost of a sway bar as well.
It's hard to be a contender in 4600 without a big wallet, but you can finish the race.
 
I agree, go with 2", it's safer and aesthetically, it looks better on an early bronco as well.

I've been thinking about your 3 link front VS a radius arm setup and I'm still not convinced a 3 link is a better option over extended radius arms.
The simplicity of radius arms is pretty great, with a 3 link you have the added cost of a sway bar as well.
It's hard to be a contender in 4600 without a big wallet, but you can finish the race.

Extended radius arms aren't a bad option, but the 3 Link will provide better geometry and put down better traction (provided it is set up correctly). As far as whether or not a sway bar will be required depends how high my roll center ends up being and how wide and high I can mount my springs. These same factors also affect a radius arm suspension, it is just that the inherent bind of radius arms helps resist body roll. Anything you do that improves articulation with radius arms (extended arms, Y-link style, etc.) will also reduce their roll stiffness.

So, to answer your concern, yes, I will probably end up needing a sway bar.
 
Probably was a good idea to build 'Sharp motorsports world headquarters' instead of pissing the same cash into a race effort. But, you need to spill something all over that new floor.
 
Running a 60 front and 14 bolt rear with copious amounts of body armor I assume? Sounds like you added about 1,300-1,400 Lbs. over a stock LJ vs. the 870 Lbs. I am guesstimating for my build. I am certainly of the mindset that light weight is the way to go and have no intentions of armor plating the entire body, but I understand what you are saying about under-building in places where you might just be shooting yourself in the foot. I was already leaning toward 2" tube for the cage for the reasons you have mentioned. There is only a ~.3 Lb/ft weight difference between 1.75" and 2" OD .120" wall tube, so assuming 100' of tube for the cage and bracing, that is a ~30Lb difference. Not insignificant, but probably worth the penalty.

I was running a Dynatrac Pro Rock 60 front and Moser 60 Semi-Float Rear. Both were heavily trussed. You will need trusses front and rear. All my armor was aluminum, but it did all add up... plus 22 gallons of fuel, a spare, and 60lbs of tools.

Also, on the tubing; you would only need to do the mains in 2" and can step down with accessory tubes/braces.

Looking forward to your build.
 
Probably was a good idea to build 'Sharp motorsports world headquarters' instead of pissing the same cash into a race effort. But, you need to spill something all over that new floor.

Funny you posted that, the next day I went into my garage, there was a puddle of gear oil under my Dana 60 :laughing: It is your fault because the pinion seal wasn't leaking before you posted that!

I am glad I got the shop built. I had some mixed feelings while I was building it since I was thinking about all the sweet 4x4 parts I could have been buying with that money (or investing it since the market had just suffered the "Covid Crash" and I probably could have doubled it). It sure is nice having a proper place to work on things.

I was running a Dynatrac Pro Rock 60 front and Moser 60 Semi-Float Rear. Both were heavily trussed. You will need trusses front and rear. All my armor was aluminum, but it did all add up... plus 22 gallons of fuel, a spare, and 60lbs of tools.

Also, on the tubing; you would only need to do the mains in 2" and can step down with accessory tubes/braces.

Looking forward to your build.

Thanks for the details. The 100' of tube was just to come up with a "worst case" comparison between the tubing sizes.
 
Got some progress done this weekend, but it has been cold and my shop is currently unheated and uninsulated which cuts down on my motivation (My damn beer froze the other day :laughing:)

I've been trying to get the body stripped down so I can pull it off the frame and make repairs, but it had been a mess of broken/rusty J-clips and other piddly crap. The dash is blocked from coming out by the cage, and many of the cage bolts are inaccessible from the bottom without pulling more crap out of the way. The inner fenders and wheel tubs are in worse shape than I thought; tweaked, lots of cracks and torn metal, and big sections that were torched out (the upper corners of the inner fenders where all Broncos rust). I think I am probably going to have to replace all these parts with new sheet metal. The fiberglass fenders are pretty rough (which I already knew) and I am not sure if they'll be worth saving since I know nothing about fiberglass repair. I have another set of steel fenders that are a little rough too, but at least they don't have torn out bolt holes. I think I'll throw the fenders on a scale to get an idea if the fiberglass fenders are light enough to justify the hassle since I would rather have dented steel fenders than broken fiberglass when they get damaged from racing.

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I ended up getting tired of working on that since it was kind of a PIA to do some of that stuff by myself and it wasn't going too smoothly. I decided to start working on the front axle instead and I got it all stripped and the old leaf perches ground off.

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I had broken the driver's side stub on my last outing and it was stuck in the spindle. I had to whip out the grinder with a cut off wheel and was able to cut off just enough of the part sticking out of the wheel-side of the spindle to get the rest of the shaft out. Obviously, the hub was toast too, but I have drive flanges that I will be using (I was already running one on the passenger side, but kept a hub on the driver's side since the diff was welded).

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I also measured the steering stroke for a ram. With the steering stops where I had them in the beater Bronco II (to keep the 38" XMLs out of the leaf springs) there was almost exactly 7" of steering throw. With the steering stops removed, I got right at 8" with the factory tie rod hitting the factory diff cover. I also measured without a tie rod and got ~9" with the knuckle binding on the "C" in both directions. I am thinking an 8" ram should be the ticket.

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I debated stealing the ARB locker out of the EB Dana 44 to run in this axle, but it is a high speed carrier (3.54 gears) and you can't get thick cut legacy HP Dana 44 gears. Additionally, I would have the added expense, complexity, and weight of an onboard air system. I decided to bite the bullet and ordered up a Grizzly Locker to keep things simple, and they supposedly don't get taken out by broken axle shafts like Detroits do. I also bought some 5.38 gears and committed to going no doubler.
 
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i like what you are doing here and seem to have a solid plan, cant wait to watch and see how this goes as should be a fun project :smokin:
 
What axle gear are you planning on running?

I think you will be well served by going with stupid deep gears for driveline reliability. The 302 will have no problem wailing at a bajillion rpm in the desert, the cooling system will benefit from higher rpm on the pump/fan and the auto trans will appreciate being well above converter stall speed. You might even be able to get away without doing a doubler or low gears in the transfer case which would further increase drive-line reliability.
 
What axle gear are you planning on running?

I think you will be well served by going with stupid deep gears for driveline reliability. The 302 will have no problem wailing at a bajillion rpm in the desert, the cooling system will benefit from higher rpm on the pump/fan and the auto trans will appreciate being well above converter stall speed. You might even be able to get away without doing a doubler or low gears in the transfer case which would further increase drive-line reliability.

I am going with 5.38s, which is as low as you can get for the HP Dana 44, and decided against going the doubler route. With the stock C4 and Dana 20 ratios, that only puts my crawl ratio at 32.6:1, which I don't think will be enough (I am an automatic newbie so I am open to input). If I put the 2.9 low gear set in the C4, that will bring me down to 38.4:1, which is getting better, but still on the high side it seems. Based on other people's automatic rigs I've driven, I think I want to be up close to 50:1, and I don't see how I am going to get near that without doing something about the transfercase. I can get 3.06 gears for the Dana 20 from Jack O'brien (much stronger than the crappy 3.15 Teralow gears that have been on the market forever), which would put me at 47.7:1 with the C4 low gear set. I think that would be pretty close to ideal. Jack also offers a 3.6 gear set for the Dana 20, but I think that would make too big of a gap between high and low range.
 
I ran into a bit of an issue today...

I was assembling my new 4340 axles for the front, and like an idiot, I pressed the U-joints before comparing the new axle shafts to the old ones. It turns out I bought the wrong shafts :mad3:

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Here I was thinking I had a '78-'79 F250 Dana 44, but the F250 application passenger inner side shaft was too long and the driver side inner shaft was too short. After doing some research, it would appear that my axle is '73-'77 F150/F100 Dana 44 with '78-'79 F250 outers swapped on. For those who don't know (like myself :homer:), the F150/F100 inner axles are 18.91" (driver) and 33.91" (passenger) vs. 18.62" (driver) and 34.75" (passenger) for F250 axles. A real F250 Dana 44 would be .55" wider than the 1/2 ton axle with the 3/4 ton outers, and may or may not have 3" OD 1/2" wall tubes (I've read conflicting information about this) instead of my 2.75" 1/2" wall tubes. In hindsight, the tell-tale give away that this wasn't an F250 axle was the fact that the driver side leaf spring wasn't cast as part of the center section like this:
yUL5azRBRh5GZXxtEiaRXUHWPdI_O47sS2EMxWXgfISH6HrniVAlXsPnY3bUPHC7MjcoFSxIx9VjedNZDA.jpg - Click image for larger version Name:	yUL5azRBRh5GZXxtEiaRXUHWPdI_O47sS2EMxWXgfISH6HrniVAlXsPnY3bUPHC7MjcoFSxIx9VjedNZDA.jpg Views:	0 Size:	61.6 KB ID:	250463



So I started doing some thinking over several local brews...
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I can cut the current axle tubes leaving 2-3" sticking out from each side of the center section casting and "C"s and sleeve them with some larger diameter tubing in order to make the axle the correct width for the axle shafts I bought, or I can just buy the correct length inners and chalk it up as a couple hundred dollar mistake.

The additional benefits to cutting the axle apart and re-tubing/sleeving it with larger tube are that I can set the caster exactly where I want, my 3-link brackets I bought were made for 3"+ tube and don't fit my 2.75" tubes, and I can substantially strengthen the axle housing in all directions. I did some number crunching and 3.5 OD 1/2" wall tubing would be 82.4% stronger than the current tubes and add 23 Lbs. I also looked at 3.75" OD 5/8" wall tube which would be 143.4% stronger than the current tubes and add 36 Lbs. With the bigger axle tubes, I am thinking that I may not need a truss seeing as Jesse Haines' Roxor isn't running a truss with Portals.

What are the peanut gallery's thoughts on this?
 
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What a coincidence I just watched this video yesterday. If the new chromo shaft doesn't neck down too much this is your ticket (would probably take you a day of work to get set up though).

https://www.youtube.com/watch?v=UxEiPyMLLOQ


I think you should just extend the axle housing though for all the reasons mentioned.
 
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