I'm sorry, let me be more specific. I sometimes make posts assuming that most folks on here understand basic engine building theory. What stepside454 said about camming and carburation is exactly true. But this stands true for any 4 stroke building, and some of the theory drips over into 2 stroke, diesel and rotary. And I agree in that I've seen a lot of guys try to make more out of a smaller motor than it can use, ie: too big a cam or carb, too big ID exhaust, etc...

That being said, when you go to rebuild either one, or any other motor for that fact, first you need to decide what you want it to do. What kind of gas you want to buy, how streetable you'd like to have it etc. The parts behind every motor are different, you are limited by displacement as to many of your choices, from cam to valve size, and from carb to exhaust and everything else in between and other things like what gas station do you want to purchase you petrol at. Do you want to buy av gas or pump gas. When I say get a good stout cam, that applies to the motor in question, don't just go out and buy a big cam for a SBC, get one for your 305. Yes they will all fit, but no they won't react the same in your 305 as in a 350, and a 400 will take more cam than a 350. This is basic theory. It doesn;t matter what motor you are building, vtec honda or BB Chevy, you are limited in what you can use that will actually help. However, the theory is the same and that depends largely on how seriously built you want your motor.

Derek