[Ohio427]

I have a 68 Camaro that I put a BB 427 in last year.The car was a roller but the previous owner had a BB 454 in it. My question is I was told that the crossmember under the transmission is a small block one because of the oval opening instead of the well known square type. The holes are offset to the passenger side in the oval opening instead of being centered in the opening. I just talked to a restoration parts person who said that he has seen GM numbered crossmembers with the oval opening. Has anyone else seen this? I used the BB motor mounts and didn't have much trouble bolting up. Is it possible to even bolt up correctly if I'm using the wrong crossmember?