4l80E into '90 V3500
 

I've searched many times on this and come up empty every time. Every swap thread I've found is either putting and '80E behind a Cummins or a carbureted engine. I want to imitate the '91 454 TBI - 4L80E combo in my '90 V3500. I have a th400 currently as you would guess. And I know that to use my round pattern NP205 T-case I'll need to use the Northwest Fab 5/8" thick adapter plate and a 2wd 4L80E, and have the tail housing machined for a VSS. I also will swap in a '91 electric speedo cluster.

My 454 is built up a little, Its a 9.25:1 oval port motor with the Comp TBI roller cam, high rise aluminum manifold and a bored out throttle body. I'm figuring with the mild port work and headers should be in the neighborhood of 375 horse. I'm running a Dynamic EFI EBL Flash computer.

My question is: Is there a factory control unit and wiring harness I can pull out of a salvage yard to make this work? I know I'd be sticking with a '91-'95 4L80E. Do the '91-'95 NBS trucks have a separate computer for the trans and just get communications from the engine computer or is it all one?

Using an aftermarket controller is last resort. I'd like to use factory stuff if at all possible.

Thanks, Nate

Re: 4l80E into '90 V3500
 

We're there not 80-91 4l80e to np205 transmissions?

Re: 4l80E into '90 V3500
 

The 4l80/205 combo was 91' only. If you search around you can find a factory setup out of a 91' just depends how patient you are and of course $$ cause they do bring good money. I've ran across 4 setups over the past couple years being parted out, so regardless of what they say about the "holy grail" and being impossible to find... blah blah. lol You shouldn't need to run the vss205 and the electronic speedo tho ( just because your swapping to the 4l80 ) and just stick with your mechanical speedo setup (runs off the tcase anyways) and save yourself a ton of work and money! I gathered up all that stuff for my 91 crew cab and boy was it time consuming searching... and searching... and searching

Re: 4l80E into '90 V3500
 

The 454 tbi should be a non issue for a 4l80e swap. I did a swap on a carb motor which is more of a pain then tbi. I used the TCI EZ CPU for the trans controller, easy install, all the controller needs to run the trans is a throttle position sensor (tbi has one), an rpm source ( take it from stock dizzy) and a speed sensor( taken from trans or tcase vss) , those 3 things and the TCI unit runs the 4l80 like a champ.

Re: 4l80E into '90 V3500
 

I see you have a '69 Blue 'n White Judge. I, myself am the proud third owner of a '70 Atoll Blue/painted White top RAIII 4-speed Judge. Two things I like are Pontiacs, and GMC trucks.

I would like the electronic speedo for being able to program for tire size, etc. There are '91 'burbans and blazers being scrapped around here all the time so I can get those parts easily.

Also, one of my dad's best friends is a machinist and has been for 30 years. He said it wouldn't take long to convert the NP205 tail housing to use a VSS. So for that I'm not worried. I already have a source for the sensor and tone ring.

I found this on the Third Gen site.


Nate

Re: 4l80E into '90 V3500
 

i dont see why you cant use the harness and ecm from a tbi 4l80e truck from the 90s. why would you need a 2wd 80e?

Re: 4l80E into '90 V3500
 

Re: 4l80E into '90 V3500
 

Re: 4l80E into '90 V3500
 

Can't you use a harness from a p-van (bread truck) or motorhome hath had a TBI 454/4l80e?

Re: 4l80E into '90 V3500
 

i dont see why you couldnt. the trucks had tbi until 96 too. theres plenty around. so did regular vans and all.