Like Bob said, I am one of those people who believe that you will crack the bellhouseing useing front mounts and a rear crossmember. Classic Chevy, as well as other companies ,I'm sure make bolt on side motor mounts to go with a rear crossmember. That said I use front mounts with mounts on my blowsheild . of course when you do that your trans hangs out in space but I have had no problems with breaking transmissions carlg