I currently own a 1986 regal limited with a 307 5.0L and have a chevy 400 motor with a turbo 350 transmission. What all do I need to be able to swap engines and transmission. Cross member? Motor mounts? And what about the on board computer I have. Will I also be able to keep my digital dash. Also wI'll it fit if it's a big block or small block 400 chevy. I need all the help I can get as I'm new to this. Thanks