Sorry to bring this old post back but I put a 72 Ventura subframe (original Pontiac 350 car) in my 68 Firebird that has a 68 Pontiac 350. Now the engine/headers sit up against the steering box. Before, when I had the original 68 Firebird subframe I had a good 1/4" gap (if not more) between the headers and the steering box. I bought the motor mounts from Ames and didn't bother to check them against the originals since they were "interchangeable". I've tried just about everything to get the engine to "slide" to the passenger side without much luck. I found this post and now I wonder if the motor mounts (insulator) were different for a 72-74 Ventura subframe. I will pulling the engine soon and would like to get this resolved before I install it again.