T-Case Swap

[btstrohfus]

just purchased a Th400/205 with the circle pattern , not figure 8 out of a 89 1 ton i believe he said. Did not recieve the crossmember. Was wondering if i could use the crossmember from my 77 3/4 ton that had th th350/203. if not what do i need to be looking for to make this work..just had the trans overhauled and new seals in the t-case, cant turn back.. thanks alot.

[btstrohfus]

i have pics of what i have, hopefully i can upload them still tonight.

[btstrohfus]

here is the 203 with the crossmember that i removed from 77 3/4 ton. And the last picture is the rebuilt 205, any ideas would help. thanks

[btstrohfus]

could i see some pics of some 3/4 ton's with a th400 and a NP205,that would be similar to my 77, interested in the how the t-case and crossmember look. thanks

[cdm10700]

i dont think the cross members are different could be wrong

[btstrohfus]

it might be me but it looks like the driveshaft will be right in the center of the crossmember? or am i mistaken

[csb#356]

The CV will keep it up and out of the way of the crossmember. That crossmember will work just fine. You will probably need to lengthen the rear driveshaft and shorten the front though. But I'm not positive with that adapter. I've only use 205s with the figure 8 adapter and I'm not sure what the lenth difference is

[rollbig79]

From what I know the crossmember is the same...the biggest change will be your driveshafts...those will have to be changed. One shortened and one lenghtend. I am planning on doing this swap on mine as well. I don't have a problem with the NP203...just not a big fan. I would rather have an NP205

[btstrohfus]

I'm also wondering what problems will I'll run into since the pickup has a 6in lift!
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[btstrohfus]

And what pickups used the crossmember with humps on either side, or both?
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[ray_mcavoy]

I believe GM changed to that humped style transfer case crossmember in 1985.

And it looks as though you'll need one of those 85-up crossmembers to work with the adapter that's pictured on your rebuilt 205.

[btstrohfus]

And will the newer crossmember fit ok, or will I need to fabricate or drill holes.
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[btstrohfus]

Ok so i think i found out what adapter i have on one site, plus the crossmember that i need on the other. and from what i can tell they newer round pattern its alot shorter which in turn requires the crossmember to have an arch to clear the front driveshaft. Does this make sense to anyone else, or am i trying to make this make sense.

the adapter i have.. #28 and #29 i believe.
http://www.pirate4x4.com/forum/engin...-shifters.html

And the crossmember i need #6-9.
http://www.pirate4x4.com/forum/engin...s-members.html

let me know what you think.

[btstrohfus]

Here is a picture of a later style t-case setup. found the crossmember on craigslist last night. hopefully everything works out and fits.

[btstrohfus]

Does anyone know the front and rear driveshaft lengths for a 454/th400/np205. I have driveshafts from the th400/np205 i recently purchased, but they were from a 3/4 1989 Suburban. I don't know if they are the right length or not. thanks

[Motor City GMC]

How did this turn out?
I am curious because i am thinking of doing similar...I have a 79 K30 with 400 sbc, th400 and np203...looking to swap the 203 for a 205 but dont have a clue what is involved???