TH400 to 4L80E swap 89 burban V2500

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Chaz

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Hey guys if i dont do a 4spd swap soon on my burban im gonna have to swap out my 4.88 gears cuz I do more on road/fwy drivin than I do offroad with this truck. What am I lookin at for the 4L80E swap?? I was told I could go with a trans out of a 91 truck cuz it has the computer attached but theyre hard to find. If I can find one, what other mods will I have to do,,,how difficult is it to move the trans mount and would I have to modify the driveshafts???? I dont want a manual valve shift and i'd prob go ahead and spend the money for the aftermarket computer to get it to work if I knew how to hook it up. If I cant do a 4spd swap im gonna have to swap out the gears cuz I dont want to blow the motor winging it down the freeway to work all the time. I had someone run the numbers and I believe the 4spd trans is the far better choice because it would kick down my rpm's more than a gear swap to 4.10,s...Oh and im runnin 35,s on a 6 inch lift 5.7 tbi so I think i need at least 4.10,s....
 

oneluckypops

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Hey guys if i dont do a 4spd swap soon on my burban im gonna have to swap out my 4.88 gears cuz I do more on road/fwy drivin than I do offroad with this truck. What am I lookin at for the 4L80E swap?? I was told I could go with a trans out of a 91 truck cuz it has the computer attached but theyre hard to find. If I can find one, what other mods will I have to do,,,how difficult is it to move the trans mount and would I have to modify the driveshafts???? I dont want a manual valve shift and i'd prob go ahead and spend the money for the aftermarket computer to get it to work if I knew how to hook it up. If I cant do a 4spd swap im gonna have to swap out the gears cuz I dont want to blow the motor winging it down the freeway to work all the time. I had someone run the numbers and I believe the 4spd trans is the far better choice because it would kick down my rpm's more than a gear swap to 4.10,s...Oh and im runnin 35,s on a 6 inch lift 5.7 tbi so I think i need at least 4.10,s....

35's I would reccomend atleast 4.56's, your 4.88's are way better suited. The aftermarket controllers would not be hard to install, everything is pre labeled and has instructions that are easy to understand.
91 is a year of its own
92-94 interchange
95-97 interchange
98 and up interchange
98 they changed the cooler line fittingins to 1 in the front and 1 in the rear, there thought was to provide better cooling. Which IMHO was NOT needed. If it wasnt for that then 95 and up would interchange on the 4l80E.

Yes driveshafts will need to be lengthened in the front and shortened in the rear. Not a big deal but a definte exspense that needs to be considered and researched.
 

thatcanuckguy

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i just went through this with a 4l60e, almost the same. all said and done, the stand alone computer set me back about $1100. seems to be worth it so far. installation was a breeze
 

Chaz

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Great so its gonna be at least 2k plus mod the driveshafts plus mod the trans mount,,,,,,,,,hmmm dont know if i like the truck that much,,,,
 

oneluckypops

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Great so its gonna be at least 2k plus mod the driveshafts plus mod the trans mount,,,,,,,,,hmmm dont know if i like the truck that much,,,,

Simple as drillinf new holes in the frame for the crossmember to rebolt to..
 

HotRodPC

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Great so its gonna be at least 2k plus mod the driveshafts plus mod the trans mount,,,,,,,,,hmmm dont know if i like the truck that much,,,,

Sumbish, I'll give that truck some love !!! 89 3/4 ton 4x4 Burb with Mini Quads and TBI. Yep Yep Yep !!! Take a look at what you'd spend on gear change. I'd do the 4L80-E swap. Would it really be a $2K swap? I guess you don't have the Trans yet huh?
 

Chaz

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Nope,,,dont have it yet,,,
 

HotRodPC

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Anyone know which year K20 Burbs came with 4L80-E? Was it just 91 or 90 and 91?
I know you have U Pull It lots around So Cal. You might keep your eye open and check often, but when you find one, pick up your driveshafts and your cores. Eventually, You'd have it all and could probably have all you needed for under $500.
 

HotRodPC

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91 Only it is then for the Driveshafts. I'd imagine the trans can be taken from later models though.
 

HotRodPC

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