Crites has motor mounts that position engine close to the firewall.You'll want it as close to the firewall as possible to make room for a fan.I had a 517 inch 460 in my 63 convertible,but threw up my hands and put a 427 in that I had.The right header hit the body mount,the engine was too tall and would require a scoop,and there wasn't any room for a fan.