Trans crossmember placement w/ TH400 72'

[ncgamedog]

I'm doing a 72' 4wd project using a 68' body. I have the rolling chassis all finished up. Haven't started on breaking down the body of the other truck yet. I will be running a SBC TH400/NP205 combo for the drivetrain. I know the transmission crossmember I have is for a TH350 since its from a 4wd Blazer (70'). I just temporarily bolted it in the stock holes on the 72 LWB frame. With the drivetrain combo I'm using, will I need to slide the trans crossmember back?? If so, how much?

That would mean relocating both the trans x-member and the little T-case mount/x-member. The transmission I'm using is the original th400 from the 68' I will be replacing the tail housing with the adapter for the 205 which is an early type, 32 spline, short input, figure 8 pattern. The adapter has the two feet for the mounts. I'd also like to know what rubber mounts to get, if anyone knows??

I'd like to find someone who has done this same thing using the same drivetrain.

thanks for any help! -Justin

You can kinda see both cross-members where they are at currently in this pic



Here is a closeup of the T-case mount/x-member before I bolted in the trans x-member, I used the 2 holes in front of it for the trans x-member

[kwmech]

Being at work at the moment and not having my reference 'stuff' I think the difference between the 350 and 400 trans in length alone is 1.75''. Then you have the adapter lengths to compare

[b454rat]

That last pic isn't the t-case mount, it's an additional brace, torsional I think, but don't really need it. I've had many a 4wd that didn't have that and never had any issues.

As for the t-case mount, pic a year of truck that used that mount. Being it's a short spline case, 77-80 3/4 and 1 ton, and 81-85 1 ton only.