Topic: 85 motor and trans to a 81 can it work?

[yota_krawler]

I am getting a 87 single cab parts truck efi 4x4, I want to put the motor and tranny into my 85 and put my carbed motor into my 81 (it has no motor or tranny) can I do it or is there a ton of work involved? It seems as if the tranny in the 81 is shorter then my 85 (but I don't have the tranny anymore). The stock front drives line are differant. My 85 is longer then the 81 so if anyone has done this let me know, and if I can do it or if I have to find a motor and tranny out of a 81-83? Thanks Cody

[79coyotefrg]

the motor and tranny will fall right in BUT  the  tcase  crossmember  will be  about 6 inches back from stock   , the 85 tranny IS  longer than the old 81 tranny was

but it will all work fine 

[Gittinit]

The driveshafts are different lengths for the 81 and so you will need redrill the pinion flanges and use the later model driveshafts. Don't bother trying to source a 79-83 type tranny and case, becouse they are weaker. You will need to fabricate a tranny mount or at least modify your current one becouse the mount locations are also about 6" further back as well.

[jimbo74]

why not leave the 85 alone and just swap the 87 stuff into the 81?

[yota_krawler [OP]]

thanks for the info. I want my 85 efi and the 81 is actually my dads and I am nice enough to give him my motor. 

[jimbo74]

seems liek a lot of work, bear in mind the wiring harnesses will all need to be swapped with each other... the 85 engine wiring wont just throw into the 81 and so on..... you are looking @ quite a large project doing 2 engine/wiring swaps....

[brainlessfool]

why not just put the 85 eng in the 81 and use the 81 tranny? and the 81 intake, carb, exh, dist, get it?

[yota_krawler [OP]]

I am getting a 87 single cab parts truck efi 4x4, I want to put the motor and tranny into my 85 and put my carbed motor into my 81 (it has no motor or tranny) can I do it or is there a ton of work involved? It seems as if the tranny in the 81 is shorter then my 85 (but again I don't have the tranny anymore). The stock front drive lines are differant. My 85 is longer then the 81 so if anyone has done this let me know, and if I can do it or if I have to find a motor and tranny out of a 81-83? Thanks Cody

I figured my 85 would be easy, take everything out wireing harness etc. and put the efi with everything in its place. My 85 is a DD and Part time wheeler, it shouldn't take that long. The 81 has sat with no motor or tranny now for 4-5 years. That is my dads deal anyway. The 81 would be a wheeler with occasional street time and no time frame. But as for my 85, it needs to be quick. 

[yota_krawler [OP]]

seems liek a lot of work, bear in mind the wiring harnesses will all need to be swapped with each other... the 85 engine wiring wont just throw into the 81 and so on..... you are looking @ quite a large project doing 2 engine/wiring swaps....

The 87 should just go right in my 85, but ya on the 81 it will be more work.

[jimbo74]

The 87 should just go right in my 85, but ya on the 81 it will be more work.

the 87 will bolt in, but you are going to have to rewire, as the carb wiring and the efi wiring are completely different...

[yota_krawler [OP]]

I am going to strip everything from under the hood out of the 87 and put it in my 85. As for the 81 same goes for that, no cutting and splicing, everything will get transfered.

[Cracker]

Does the 81 have any lift?

My 80 came lifted, maybe 3"-4". Mine has a 22R/dual sidedraughts, and I swapped the POS L52 out for an R151 (basically the same length as your 85 tranny.) The 84+ trannies are 4 1/2" - 4 3/4" longer, I dont remember which.

All I had to do for the swap was to drill an offset bolt pattern into my pinion flanges, and I installed a Budbuilt crossmember.
I was able to use 86-88 stock driveshafts. I think I've read that some guys re-use the stock crossmember by bolting it into the back two bolt holes on the frame, and welding in angle iron to the frame to bolt the xmember rear bolt holes to.

Also, the shifter hole in the floor was already hacked apart, so I dont know if you might need to do any tranny tunnel cutting.

But its a pretty easy, straight forward swap. You have all the parts you need from the 85 & 87. Most $$ you would be out as far as the tranny would go is if you decide on an aftermarket crossmember. If you cant weld, go Budbuilt. His bolt on with Ubolts over the frame.

[THE ROCK]

 :therethere:1st and 2nd gennie motor mounts are different

[yota_krawler [OP]]

wow dug up from the grave. I forgot about this thread. (note the date May 07)