[TA454]

You want to use moroso solid motor mounts for a 72 camaro (the last year big block was available). As far as the trans your trans cross member will work as long as it is for a th400. As that cross member is different from the th350/4speed. Solid motor mounts are a good choice but i would suggest against the solid trans mount. go with a poly trans mount you need to allow a little movement or you will crack your trans case. If you do not have the crossmember for a th400 you can move your 350 crossmember back and bolt it to your 400. Once it is bolted to the trans you can square it up to the subframe and drill new holes. That is what i did with mine i laid everything out and drilled a .406 hole thru both rails of the frame on each side. I then opened the hole on the bottom to allow the head of the bolt thru just like the original mount location. Hope that helps
Chuck Zeek