I have access to a 390 for cheap and found a thread where it does fit, however i do not know what transmissions will go well or what kind of power i will be looking at. I also understand that my 71 straight six will need a suspension upgrade, but i am not really sure what this will consist of. thank you for your help.
Yup, definate undertaking. So much that I had a built 390 and C6 already ready to go, could have pulled from one vehicle to another, but I didn't do it. To much work Shock towers are in the way, C6 wont fit in the tranny tunnell without lots of mods, etc. Youd be better off with a small block of some sort
Yes, a 390 is a pretty wide engine. Plus it is longer to boot. Also a C6, which you better be running behind a 390 is a long, large around tranny. Not to mention that the bell housing in itself is a pretty large chunk of metal.
390's a great motor, just not in a Maverick, unless you plan on converting to a Mustang II front suspension.
You can always run a C4 behind the 390. If they hold up behind a 429 and 460 it will be ok behind the 390.
I know you can get an "AOD" adapter for the FE big blocks. that would probably be a better deal for the effort.