TH350 to TH400 swap

[Airwolf]

I have a 1979 Blazer and am in the process of swapping a TH350 to a TH400. what all is this going to take? I am doing this alone and have forgot most of my auto knowledge due to using it over the years. Any help would be greatly appreciated. It also has a NP205 transfer case.
I have everything out as of now, but stuck as to hooking up everything from 350 to 400.
Thank you in advance.

 

[76zimmer]

what transfer case is behind the T350? and will you run the 205 or your present t/c (203?)

 

[4X4HIGH]

You will need a TH400/205 adapter and shifter, swap the 27 spline 205 input for the correct 32 spline input (32 short input), move the crossmember rearward the correct amount, shorten rear the driveshaft and lengthen the front driveshaft.

 

[Airwolf]

Thanks for the help

The TH350 had the NP205 behind it. I will be putting it back in with the TH400. Anything else I need to do?
You all are wonderful help, I wish I had you guys here in Oregon to help me with this task I have taken on.
Thanks again for all of your help.

 

[4X4HIGH]

You will need to tear the 205 completely apart and have someone machine the case for the larger input bearing that is used with the 32 spline input gear.

 

[76zimmer]

Quote "You will need to tear the 205 completely apart and have someone machine the case for the larger input bearing that is used with the 32 spline input gear."

Unless you use the conversion shaft for the T400 output. It has a 27 spline to match the 205 that was behind your T350.
And yeh, I have one if your interested PM me.

 

[4X4HIGH]

Probably easier to tear apart the t-case than the trans though.

 

[76zimmer]

I won't argue that!

 

[warwgn]

The TH400 has an electric kick down and the 350 has the cable, so you will need to get a kick down switch:
http://www.summitracing.com/parts/BMM-20297/

that will fix you up for your install, along with all the above.

 

[76zimmer]

your 205 is a figure 8 pattern to it then right?
I have a round pattern laying around right now.