engine & transmission for 77 MGB

[BROWNJAG2]

Hey: I am in Murrells Inlet, South Carolina. I have bought a 77 MGB with a 2.3 Ford engine and automatic Transmission installed. I want to install a 302 Ford . My question is it would seem logical to use the 87/88/89/90 Ford Mustang HO engine and automatic tranny. Do you have any idea which would work best...car is for pleasure and cruiseing...no racing.
Thanks,
Len