Sandersons are the only ones that will fit w/o major modification. I did have to do a small (~1/4" frame relief on I think the driver side.) I put a 396 in my 65 - pretty much bolted right in. Used stock small block motor mounts moved forward a couple inches - there were factory holes in the frame already. Used a 6 cyl fan and spacer - had to shorten the fan spacer a little to clear the radiator. Only heat issues are the starter - header dump almost touches the starter end and it turns over real hard when hot - going to look at one of those hi torque mini starters.
