In need of some 273 head education

I would/should run a 360+ cube motor in my 66 Dart but the HP273 is the stock motor. If I wasn't interested in keeping the car original I would do that.
When I first started looking, I wanted a 64 Dart with a slant 6 so I could
hot rod it and not feel guilty about it. In 66 there were only 1237 HP273/
4-speed Darts made and that includes hardtops and convertibles. I choose to keep mine original. toolmanmike