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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: RivMan on October 02, 2010, 11:24:29 am

Title: Transmission Swap - TH350 to 700R4
Post by: RivMan on October 02, 2010, 11:24:29 am

Hey guys, I'm looking at swapping the trans in my truck, and I'm wondering what else will have to be swapped out. Will the transfer case (NP203) bolt up? Will I need new drive shafts? Cross member? Anything I'm not thinking about?

1976 K10
350
TH350
NP203 Part Time converted
D44 / 12 Bolt (3.73's)
33" tires

Thanks
-Rob

Title: Re: Transmission Swap - TH350 to 700R4
Post by: Lt.Del on October 02, 2010, 11:46:25 am

this question gets asked every few months.  Use the search engine on this site and type in some key words, you should be able to read past histories from others who have done this common transition.  The crossmember will need to be moved back, driveshaft size adjustment will most likely be needed.

Title: Re: Transmission Swap - TH350 to 700R4
Post by: RivMan on October 04, 2010, 07:51:14 am

I tried the search, and I can't seem to find much on the 4x4's, seems mostly a 2wd thing. I'm mainly worried about the transfer case bolting up.

Thanks
-Rob

Title: Re: Transmission Swap - TH350 to 700R4
Post by: Grim 82 on October 04, 2010, 09:34:46 am

I think you will need a different output shaft on the trans to use the TH350 to 203 adapter.
Without turning this into a 203 vs 208 thread, I will say that the cheapest and easiest route would be to find a donor truck with a 700r4/np208 combo and take the whole works.