4600 - Chevy Trailblazer SS everyman

Over the past 5 years we have all been forced to watch corporate backed teams dominate the "every man challenge". I think I'm at a point in my career that i have a combo of knowledge and the platform to challenge them. I've worked on cars that have been on the podium at hammers and other races, but never built something for myself. I respect that Ford takes the off-road industry the most seriously of all the manufacturers right now, but they also ruined my favorite race.

I've started on the build, i took initial corner weights and am almost done fully tearing it down. I was going to measure COG height but decided it didn't matter at all. I'll be starting on the cage this weekend but final cage fitment will have to wait for seats and suspension so i can land tubes into suspension points.




Here's the current plan:

Motor: Stroked 6.0 LS2, aiming for 550 horsepower, reliability is the ultimate goal as i will be racing a full desert series as well.

Trans: 4L65E

Transfer case: Behemoth w/ 4:1 gears

Front Diff: Later gen GMC 2500 HD IFS diff (essentially a dana 60 center section with flanges) shortened... or a 9" which would be easier probably.

Steering: "trophy truck" rack fits easily within 3" of OEM mounting location (per rules)

Rear Diff: Shaved 14b/dana 60/9", still not sure, cost vs weight vs parts is all playing into it.

Shocks: A couple companies have reached out but I'm not sure what I'll run, i have my own version of a cactus cooler using tesla valves to recirculate fluid I've designed for this since we are limited to 14" 2.5s. Should help keep temps down.

Front suspension: Typical boring IFS stuff. The front end leaves a ton of room for extending control arm length inward and the mounting options are surprisingly good. All the crossmembers in the front unbolt (the OEM IFS setup is whack) which gives tons of room for fitment. I'd be extremely happy with anywhere between 16-18" of travel but ultimately CV bind will be the deciding factor.

Rear suspension: Upper triangulated 4 link, coil sprung, 14x2.5 smooth bodies. Hoping to get over 16" travel bumped and strapped but having issues finding good coil spring options that support that.

Wheels: Forged 17" beadlocks of some kind, will probably spring for 27" tire liners as well. 35"s don't leave enough meat and I've seen so many races lost from stupid tire issues over the past 15 years I've been attending.

General/misc: Remove back hatch, tube doors, boatsides, 1" body lift for clearance and serviceability. Will be running massive oversized coolers with multiple fans, multiple fuel pumps, etc. Still haven't settled on fuel cell size or what coms to use but I'll burn that bridge when i get there.



End date is November for the build so that i can pre-run adequately, this is an absolute hard deadline and i will not skip pre-running/testing and still take the starting line.


Before you ask, why dont you do _______, feel free to read the rulebook: https://kingofthehammers.com/wp-content/uploads/2025/12/2026-Ultra4-Rulebook-V6.6.pdf
The rules make no sense to me, but they do favor the trailblazer. I'm just saving this thread for future updates :)

I'm not the usual 4l60 is a hot piece of garbage bad kinda guy, but I hope you've got some budget for that trans.

Otherwise, seems fun.

In. This will be interesting.

Keith said:

I'm not the usual 4l60 is a hot piece of garbage bad kinda guy, but I hope you've got some budget for that trans.

Otherwise, seems fun.

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4600 rules say you have to retain the stock transmission.

Is this Pharr's Touareg saga 2.0 ?

WEW said:

Front Diff: Later gen GMC 2500 HD IFS diff (essentially a dana 60 center section with flanges) shortened... or a 9" which would be easier probably.

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Uh, wut? Isn't the GM 9.25 IFS some GM in house engineered clamshell?

YotaAtieToo said:

4600 rules say you have to retain the stock transmission.

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I didn't say he needed to swap to a different trans. Maybe to clarify... he should dedicate some money to help that thing live as long as possible.

Maybe that's more clear.

Keith said:

4l60

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4l65 is slightly better.

In for the updates. I'm really curious on what this thing ends up weighing. They are pretty tanky in stock trim.

In, thanks for the chance!

They changed the rules to let you shave some weight though. I used frame brackets can come off now and front and rear cross members can come off for bumper and winch purposes.

Although, 4600 class rep still argues that one. Guy either doesnt know how to read or doesn’t know how to write a rule. Either way, heck with him.

bad zuki said:

4l65 is slightly better.

In for the updates. I'm really curious on what this thing ends up weighing. They are pretty tanky in stock trim.

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^previous post in reply to

WEW said:

Steering: "trophy truck" rack fits easily within 3" of OEM mounting location (per rules)

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go give JR4X thread a read. steering box is better and more reliable.

WEW said:

Shocks: A couple companies have reached out but I'm not sure what I'll run, i have my own version of a cactus cooler using tesla valves to recirculate fluid I've designed for this since we are limited to 14" 2.5s. Should help keep temps down.

Click to expand...

just make sure they will allow someone else to tune them, shock companies will group you with their 'free days' and they give you very little attention

WEW said:

Front suspension: Typical boring IFS stuff. The front end leaves a ton of room for extending control arm length inward and the mounting options are surprisingly good. All the crossmembers in the front unbolt (the OEM IFS setup is whack) which gives tons of room for fitment. I'd be extremely happy with anywhere between 16-18" of travel but ultimately CV bind will be the deciding factor.

Click to expand...

dont get too carried away chasing travel numbers, motion ratio is the enemy of top take off reservoir shocks

wvracer821 said:

Is this Pharr's Touareg saga 2.0 ?

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He’s legit. Out of anyone I would least expect this trailblazer to turn into a 4 year long build thread milking

Cool, been waiting for this since you discussed it on the podcast.

Size wise, how does it compare to a 2 door bronco?

triple_fcked said:

He’s legit. Out of anyone I would least expect this trailblazer to turn into a 4 year long build thread milking

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I didn't realize this was Wheel Every Weekend doing the build! My hope of this actually going somewhere and being competitive just shot up 10x!

Hell yes! Glad to see you post on here about the build!

In for IFS tech!

Following. Bench raced this platform to death a lot of years ago with the poor boys crew, surprised no one pulled the trigger on this yet. Great engine and suspension combination possibilities.

Mr. Mindless said:

Following. Bench raced this platform to death a lot of years ago with the poor boys crew, surprised no one pulled the trigger on this yet. Great engine and suspension combination possibilities.

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Never woulda thought.

Keith said:

I'm not the usual 4l60 is a hot piece of garbage bad kinda guy, but I hope you've got some budget for that trans.

Otherwise, seems fun.

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4l60/65/70 are all the same case so theyre essentially all allowed. The SS trim had a 4l70e which is the same as a 65 externally however it included an additional speed sensor. Once the transmission is built to a certain point the specific number doesn't matter because they are using the same internals. The trans i have for it is rated to over 1,000 horsepower and im running a 125k BTU cooler though i may swap that to run a cooler with dual fans for redundancy.

Tryloff said:

They changed the rules to let you shave some weight though. I used frame brackets can come off now and front and rear cross members can come off for bumper and winch purposes.

Although, 4600 class rep still argues that one. Guy either doesnt know how to read or doesn’t know how to write a rule. Either way, heck with him.

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Yeah "unused brackets", but it's probably less than a 20 lb weight savings. If you combine that with what constitutes a "temporary factory crossmember" vs a "permanent factory crossmember" you can cut alot off. I am being as conservative with the rules as possible and taking every line as strict as possible. If there is a grey area i am not taking advantage of it, i aim to be fully within the rules, i aim to not even go backwards on course a bunch of times lol.

mobil1syn said:

go give JR4X thread a read. steering box is better and more reliable.



just make sure they will allow someone else to tune them, shock companies will group you with their 'free days' and they give you very little attention



dont get too carried away chasing travel numbers, motion ratio is the enemy of top take off reservoir shocks

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I have room for a box and swingset but if i have the room to mate the steering shaft to a centered pinion on a rack a 2.75 or 3.0x6 rack would be easiest for me.
I will be doing the shock tuning.
I have found that shocks are much happier working at a motion ratio personally.

LScout800 said:

Cool, been waiting for this since you discussed it on the podcast.

Size wise, how does it compare to a 2 door bronco?

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It is about a foot longer than a stock bronco which i am personally a fan of. I've always been curious how long the 2 doors end up once they have the front portals on and are fully built, i think the rules are dumb (which is the point of this build) but i would be surprised if they were within stock wheelbase + 3". When i built Bilstein's bronco I sized a photo of it in CAD overlayed to a photo of a 4600 build and estimated they are at 107" but the remaining lens distortion could create the difference.
I will be competing at all the desert races that has 4600 cars of any kind, KOH is just 1 of many events for this build.

Progress has been much slower than i wanted with NORRA taking up some of my time.

The interior took up my 3 yard dumpster 3 times so i had to wait for trash pickup twice. I only broke 1 window removing them all, which I'll take as a win.

The engine has all the parts ordered and machining will start soon, even on pump gas it's going to make too much power for 4600
The trans is being built right now but only really helps me once i have both
I ordered 1" pucks for the body lift but may make my own body mounts later on... i just needed something easy to figure out spacing for the cage
I have enough leftover DOM i technically don't have to buy any, but i don't see the point of running tubes under 30" in length in 1.75x.120 vs 2"x.095 (what the rules allow), as the 1.75x.120 is slightly heavier and slightly weaker (though not significantly). The smaller diameter supporting tubes do look cooler IMO though.

I have an iron block 376 here and 4l60 im gonna use for mockup. I'm getting really anxious about my November deadline. I need to have the car fired up by September to be on schedule.

I've essentially ironed out all the drivetrain, im running 6.2:1 gears in the rear with a set of Jeep 6" lift dual rate coil springs mounted at a very slight angle. It's hard to find coil springs that do enough travel even with the sort of "tender spring" style ones that are so common.
I thought about running square tube as a keeper for 3.75 ID springs with some retainers to get the length and travel that i want (and also i have take-offs here for free) which is still a separate coil spring but i don't want to give anyone a single excuse to complain about rules.

We have a set of hmmwv portals that i am using for reference and I'm considering machining an upright for them, although i really wanted to do this without portals.
My thought is that it will save me long-term cost on CV axles (lower angle/strength) and front diff size, so i could run a normal 9" low pinion with 3.25:1 gears flipped upside down. I'm not really running them for the strength from the gear reduction necessarily, the biggest thing they fix for me is the outer CV angle at full droop/full lock. The rules are stupid so you cannot take 5 seconds with a hammer to clearance the inner fender well like every "stock" style build on the planet... so although i think portals on a full body vehicle not designed for them doesn't make sense for most customers, for this class i see the appeal.

I will still be all for removing portals from the rules. Currently 37s and IBP's are not allowed despite vehicles coming with them stock... which to be fair, is very cool and we have Ford to thank for that. In contrast to portals not appearing on these stock vehicles but being allowed. It's a massive barrier to entry with the rules written to favor them and really detracts from what i want the class to represent.

The body mount pucks will be here next Wednesday so ill start on the cage then.


I hope everyone had a good memorial day weekend. The amount of folks reaching out to offer help and support is really humbling so if you're reading this i just want to say i appreciate it even though i don't really know how to show it.

Unless the rules change 1 and 2 on the podium are going to be portal rigs, so build to be on the podium.

If you are hoping to finish by November I doubt you will have time for portals.

LScout800 said:

If you are hoping to finish by November I doubt you will have time for portals.

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I'm already drawing up my own uprights, adding the gears into them isn't too much more time since it's already getting machined. The biggest add-on from doing it is I'll have to make the upright 2 pieces that bolt together, mostly so i can make it using remnants which saves me cost, but also because the kingpin nut is right where i want the lower control arm to bolt to it.
My workload is pretty rough right now. Because the portals save me money on diff/cv cost i can justify more time away from my day job... that's what I'm telling myself at least.

WEW said:

I'm already drawing up my own uprights, adding the gears into them isn't too much more time since it's already getting machined. The biggest add-on from doing it is I'll have to make the upright 2 pieces that bolt together, mostly so i can make it using remnants which saves me cost, but also because the kingpin nut is right where i want the lower control arm to bolt to it.
My workload is pretty rough right now. Because the portals save me money on diff/cv cost i can justify more time away from my day job... that's what I'm telling myself at least.

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Just my opinion but the hummer gearset will be the weak point. I don't think the upgraded ones that Jesse sells will hold up to landing on throttle and shock loading in the desert.

The rock crawler guys are still breaking them and the 74weld ones with less motor.

November is an ambitious goal but I like it !

Cool build!

if you show up without portals, you are a going on a really expensive miserable trail ride.