Little history: Got 79 firebird. started it's restoration. 87 TA motor can't handle anymore and it gets put on the back burner because funds are going towards the 79. Now, I was working on the 403 for the 79 the other day and realised that I still had the 400 sitting in the corner I pulled from the 79...I decided to use that in my 87...but as i said before, my funds are going towards my 79 and I just don't have the money to spend on a spohn crossmember to work with the pontiac th400. Anyone ever fab a stock crossmember to work a th400 and stock TQ arm?

 

I have not fabbed one for a TH400, but I did for my T56. You do know how to weld I'm guessing. If your looking for a starter point, just do what I did. First off, cut all pieces too long. You can trim them later but its harder to make them longer. I used 90 angle for most everything and plate to join everything. Then just cut a piece and bolt it to the trans mount. Then cut two more pieces and bolt them to the frame rails where the trans crossmember bolts too. Then its just a matter of seeing how to join all 3 pieces together while leaving room for exhaust if its going to be ran down the trans tunnel. If your looking for this process in pics, go to my cardomain page in my sig and its on page 3.

 

Thanks for the info. I am pretty good with welding and metal fab, just wanted another opinion if it was practical as well as doable. Thanks again. If anyone else has anything to add I'm always open for as much info as I can get.

 

I made both a crossmember and torque arm bracket. I had an old crossmember from 86 camaro and used 1/4 plate to extend it. I also used 1/4 plate for the t/q arm mount. I can send pic if you want.

 

Dustytrix, I'd appreciate it if you could send me pictures of your crossmember. You can email them to knight_research@yahoo.com. thanks.

 

I had to work late today but I will try to send them tomorrow

 

 

Are you moving the frame mount back ? Not sure why you need 6" of difference.

 

If your asking me the 400 and 700r are not the same length. So the transmission mount is not located at the same place. I kept the cross member in the same location and moved the mount forward.

 

Didn't think it was that much difference now you got me thinkin.

 

There's at least 3 different tailhousings for the th400... I wouldn't count on them all being shorter, like I bet the ones from a late 60's/early 70's Cadillac wouldn't fit at all, they're _much_ longer (of course, those would have a different bellhousing, but I believe they used them in some trucks behind a chevy)

 

I made mine. Made it from the old crossmember and a peice of 1 1/2" rollcage tubing bent in the shape of a U. I have a store bought crossmember and torque arm mount that I want $50 for it if you just wanted to buy one. I made mine because it gave me more room for the dual 3" exhaust.

 

TB2, PM sent