Trans Crossmember Modification

In order to use true dual exhaust pipes from the headers back on G-body cars, the tranny crossmember needs to be replaced with an aftermarket piece or the current one needs to be modified.

I used the Transmission Mod Page on MalibuRacing.com as a basis for my chop and weld. Basically, I tack welded a piece of 1/4 in thick steel over the place where the exhaust tube would go. Then I chopped the piece of crossmember out with a mitre saw mounted with a metal cutting blade and then a hack saw. I then finished the weld with a wire feed welder.



One problem with my mod was that the crossmember flexed quite a bit when it took the weight of the tranny. I added pieces of 1/8 in thick steel to make the plate into a I shape. This helped a bit, but the crossmember still flexes. I should have used 3/8 in thick steel plate for the main piece.




Also, I cut the piece out perpendicular to the crossmember. I should have cut it along the line where the exhaust was to go. This caused me to have extra bends in the exhaust tubing.

Overall, the project worked fine. Now that I'm considering going to a 4 speed 700R4 transmission, I may have to do it again on the 700R4 crossmember.