What would You Choose and More Importantly WHY?

Do the slant with the 4-speed, and I agree with Dan - the OD is a great way to go. Going to the 273 is so common. An honest 215HP out of a slant is nothing to sneeze at. And besides, it's easy to make it look like a sleeper. When you spank some punk in his rice rocket you can pop the hood and let them know they just got beat by 50-year old technology.