What will fit / work?

You will need new motor mounts for a 340 & 360.
You are right about that...I should of been a little more specific about my question. I've mainly dealt with early 273's and 318s...There are quite a lot of LA engines here to be had locally. My main concern was encountering problems (mount location etc.) in the application of the "newer engines" (80s and 90s) in a 65 chassis.
Norm