Tom, we see a lot of swapping around in the South. Guys use whatever is hanging around, or whatever is cheapest. My own cousin put a Chevy 350/Turbo-Hydramatic 350 in a Fox body Mustang, then he sold it.
I guess the bottom line is, nobody can tell you what to do with your stuff. If you want an FE, it's your money and your car so go for it.
I have a 292 Y-block in our '59 Galaxie. Folks around Detroit LOVE to see an original correct engine. When I start it up, the sweet sound from that "Y" is like no other. It's perfect for cruising.
A 390 can look identical to a 352 in a Tbird, but what a dramatic difference in torque .285" increase in stroke makes with .050" more bore TIMES 8! It's not the increase in displacement, it's the longer lever of the crankshaft.
Want 40% more ponies? That's what Paxton and Vortec superchargers deliver. (Nitrous, too.) Whatever tickles your fancy, there's plenty here to make into whatever you like. - Dave