[Alex]

Originally Posted by Shadowjack

There are only two crossmembers for '64-'72 Pontiac A-bodies: ones for standard unboxed frames and ones for heavy-duty boxed frames. Transmission irrelevant.

I ran across this old post while doing a search.
I'm in the process of rebuilding My '68 LeMans Convertible.
The Car came with a 300 2 speed, and I going to put in a TH 400 short tail.
Looks like our sponsor only sells 3 cross members.

64-72 hardtop
64-67 convert
68-72 convert

So I should be alright with the same cross member. Part # 9796242 just move it to the right set of holes in the frame.
I'll post this in the 68 69 forum also.
Thanks in advance.