I guess the main question is how are you going to use the car? Mainly street with the occasional 1320, autox, road course or is it going to be the occasional Friday/Saturday cruise with a visit to the track every weekend?

I faced this question several years ago with my 67 Dart GT. Since the car was mainly a street visitor And had manual steering I went with a 360. He built a motor that pretty much had the torque and hp equal to similar big block without the added front end weight. The car would go low 13s all day long and was limited in going faster due to chassis and limited rear tires and gearing.

The car is now in OZ, the new owner made some mods, went with a small block stroker tubbed the rear to get more tire, made some minor front end mods and now the car gos in the low 11s

Owning a big block Dart now I can see a vast difference in handling running a big block vs a small block A body.