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Less tarded ls swap

ConwayMuddy

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May 19, 2020
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Jerkwater wi
I need to swap out the TBI 350 in my 91 turdburban, apparently the knocking wasn't a cracked flexplate :homer:. 91 burban, 350, 700r4, np241, I'm trying to figure out the least retarded way to huck a 6.0 ls in it.

I have an 04 lq4 dbw sitting here, p.o. cut the harness, but I have the pedal and computer. I know dbw wont work with the kickdown cable on the 700r4, but I remember finding someone making the bits for dbc throttle bodies. For this swap I'd need a new throttle body, kickdown parts, stand alone harness, I believe a different ecm, and a bushing for the torque converter, I believe that's all.

option 2, same lq4, but find a 4l80e. I dont know if I could use all the dbw stuff this way and avoid buying dbc bits and pieces. Havent found a 4wd trans, would the tail shaft housing off the 700r4 swap on to a 4l80? I know the 700r4 is the predecessor to the 4l60 but I dont know about any physical differences.

option 3, find complete engine, trans, and transfer case to swap in. Would probably try to find a running truck for this, so far it's all push button cases. Dont know if I could swap the current case to the new trans, or swap my manual shift parts to an electric shift case.

I'm sure I'm forgetting some things, any input is appreciated. Let the flaming commence :flipoff2:
 
Unless you are planning to spend a truck load of money building up the 700r4, just find a 4l80e.... probably spend a shit load less money. You couldn't give me a "built" 700r4 for a swap behind a 6.0L.
 
700r4 has about 3000 miles on it according to the woman I bought the burb from. Had it rebuilt then the engine sprung a massive and misdiagnosed oil leak, truck was parked. Not a hardcore wheeler, just a hunting truck and winter beater.
 
I would avoid the 700r4 my dad's '89 Blazer has had plenty of them. Since you have the chance I would just upgrade now.
 
Any ls tcase will be driver drop and a turd on a freshly mowed yard. Which tcase is it? 241? Being a 91 it is already a vss speedo so that helps the ls setup. 700r4 is 27spl and square boltpattern 4l80 is 32spl and hex bolt pattern. If youre a 241 you can swap the input and the tcase is handled. Im not a fan of 700r4 either but they do have a lower 1rst gear and dont suck as much power as the 4l80 will
 
If you go 4L60e you can retain the 27 spline transfercase though I'm not 100% sure if it will clock out to exact same angle. I would hit up junkyard and get the trans\computer and engine wiring while your there. I think site is called LT1 swap that has full manual on how to make stock harness into stand alone. If no luck local maybe online place like LKQ and get lighter parts or buy a wrecked full truck.
 
Since the harness is hacked, why not purchase a Holley Terminator kit? You are likely going to spend $400 on a harness anyway plus paying someone to program out the things you don’t want?
 
"Rebuilt" doesn't account for shit on a 700r4... in the past, I had 3 rebuilt(one dealer done) and they never lasted to 20k. Unless you have a receipt showing quality upgrade parts, I'll still give you a no thanks to one. I'm sure you can find some sucker that will pay a premium for that 700r4 that will easily cover a 4l80.

The VSS issue can be resolved in the 4l80e relatively easily so the tcase doesn't matter: you can add the 2wd rear drum to a 4wd 4l80e and use the second port in the 4l80. I believe it is rear drum... I did this on the 4l80 in my 5.3L project. No problems from the trans shop.
 
350TacoZilla said:
If you go 4L60e you can retain the 27 spline transfercase though I'm not 100% sure if it will clock out to exact same angle. I would hit up junkyard and get the trans\computer and engine wiring while your there. I think site is called LT1 swap that has full manual on how to make stock harness into stand alone. If no luck local maybe online place like LKQ and get lighter parts or buy a wrecked full truck.

local junkyard isnt big on selling parts anymore, from what I've heard they dont make enough to justify anything other than sending stuff to the crusher. They have two running 2wd 6.0 trucks for sale. Does the tail shaft and housing swap from a 700r4 to a 4l60? Closest lkq I'vefound is 3 hours away.

[memphis said:
]Since the harness is hacked, why not purchase a Holley Terminator kit? You are likely going to spend $400 on a harness anyway plus paying someone to program out the things you don’t want?
this wouldnt be a bad way to go, but I really only need emissions, vats, and whatever basic junk programmed out. Not looking for a hot rod, just something more reliable than a TBI treefiddy that sounds like a dryer full of hammers.
 
700r4 has about 3000 miles on it according to the woman I bought the burb from. Had it rebuilt then the engine sprung a massive and misdiagnosed oil leak, truck was parked. Not a hardcore wheeler, just a hunting truck and winter beater.

And it needs an anything-swap why? Can't you Chevy guys buy a brand new crate 350 for $1200?!? /jealous/
 
subybaja said:
And it needs an anything-swap why? Can't you Chevy guys buy a brand new crate 350 for $1200?!? /jealous/

I'm sure I could get a crate motor, I've got a good TBI 305 I could drop in. Just an improvement going ls, hopefully anyway. Gives me something to learn, eventually I plan to stuff a 6.0/ 6l80 into a 60 Chevy wagon
 
FWIW most 2wd 4l80e have a fully splined 32spl output shaft, you can cut it, do a little grinding and put a factory 4l80e 4wd adaptor on it.

and buy the $10 factory freeze plug to keep it from over filling your t case:laughing:
 
Check out car-part.com, I'd be damned surprised if you had to drive more than a couple hours for a 4L80...
 
And it needs an anything-swap why? Can't you Chevy guys buy a brand new crate 350 for $1200?!? /jealous/

Kinda what I was thinking. Mpg, will probably go down with a 6.0.:laughing:

Headers, chrome intake and a 3/4 race cam it will probably keep up with the 6.0 anyway :flipoff2:
 
Bringing this back up. What's a decent value swap radiator? I keep finding ones that need hose end adapters threaded in, or super generic ones.

Also, I keep thinking about going with a holley harness and programmer. Currently dbw, any benefits going to dbc ? Been a minute but I believe dbc setup was cheaper, not accounting for a throttle body.
 
Decide on the 4l80? Lots of companies make new stand alone harness for factory ECU. Wayne hartwig still in the game?
 
If you want to go Terminator with DBW, make sure your pedal and throttle body are compatible. I find the terminator much easier to work with than factory tuning.
 
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