1985 6.0 swap

[pkraemer1985]

Need Help With My LS Swap

Okay, this is my first swap i am doing. I have a 1985 Chevrolet pickup. i recently picked up a 6.0 and a 4l80e transmission to go with it. Ive been looking all over the place for this answer and cant seem to find it. I want to know where i have to place this motor and trans in my truck where i can keep the driveshaft i have currently. i am using a 350 and a muncie m20. is it 1" back, 1" forward of the original mount? i have no idea. hopefully someone would be able to tell me before i find out with trial and error. Hopefully i can get the engine/trans in soon.

 

[Old Painless]

I had a 6.2/700r4 in my 85 that I swapped for a 6.0/4l60e - factory driveshaft was barely too short, and I ran the engine almost all the way to the firewall. I'm probably not much help since the setup is so different, but hopefully this gets the ball rolling for you.

The factory shaft on my truck was 55.5 (appx) yoke to yoke. I think 80's are about an inch longer than a 60 but double check that.

My driveline was about 3" too short, but I fabbed my own motor mounts to adapt to factory clamshell just for brevity and ease. I think you'll have a hard time finding that extra room even if you have a driveshaft the same length as mine, and I'm pretty sure there's only a few others that are longer without having gone split.

The issue you'll have trying to get that motor as far back as possible will be a. Intake hitting the firewall, and b. Oil pan hitting the crossmember if you try to tuck that thing down for more room to firewall.

It seems like there isn't too much room to mess around unles you go aftermarket pan, and I doubt a lower profile intake will get you much either.

Having that said a new driveshaft isn't a terrible thing to spend money on especially if you're going to soup the thing up.

 

[evl]

Get yourself a set of the adjustable motor mount adapter plates that bolt to the ls engine. There are about 4 places to mount the clamshell mounts. The last set I got were from flea bay. 30$ shipped.This would be your best route to trying to reuse your driveshaft. Good luck with the project

 

[Camar068]

After the one I'm working on, the next LS swap I do will have a 6L80 in it. I want it so bad I can taste the NP205 and adapter needed for it.

 

[evl]

I have done 2 swaps with the 6l80e trans. First truck was an 85 half ton 4x4. Used the ly6 6.0 engine and 6l80e. If you use the np208 trans from a th400 it will bolt up to the 6l80 trans, as long as it was an original 4x4 trans with the original adapter.
The second truck was a cucv, we used a l92 engine with 6l80e trans. Also used the original Transfercase from this truck. We used the adjustable is adapter plates in this truck, pushed engine as far back as possible and we did not need to cut the driveshafts. Both front and rear bolt on almost scary perfect. Below is a pic of the 6l80e trans bolted to the np208 for your reference

 

[Camar068]

awesome, good to know it's not just the NP205 I can use.

I have done 2 swaps with the 6l80e trans.

Looks like you didn't need a different adapter either. Sorry to original poster for hijacking your thread a bit.

 

[Camar068]

hmm.....wonder if I can change the input spline to 32 and be done with it...the search continues.

 

[evl]

Yes you can convert the input over on a np208 to 32. We did that in the first truck

 

[Azathoth]

I have done 2 swaps with the 6l80e trans. First truck was an 85 half ton 4x4. Used the ly6 6.0 engine and 6l80e. If you use the np208 trans from a th400 it will bolt up to the 6l80 trans, as long as it was an original 4x4 trans with the original adapter.
The second truck was a cucv, we used a l92 engine with 6l80e trans. Also used the original Transfercase from this truck. We used the adjustable is adapter plates in this truck, pushed engine as far back as possible and we did not need to cut the driveshafts. Both front and rear bolt on almost scary perfect. Below is a pic of the 6l80e trans bolted to the np208 for your reference

Was the 85 a SWB or Long? I'm a little worried on mine about having enough room to relocate the cross member. I've also got 4-5 inches of lift and am worried about the driveshaft angle.