[nymathboy]

My vote is for the 351w.

My reasons
1) More cubes make more power when all else is equal
2) A smaller engine has more stress on it to make the same power
3) If you super or turbo a 351w you make big power
4) Thicker block when comparing apples to apples
5) Stroke a 351w to 392 or 408 and again you have huge power

If on a budget you can get a 351w from a yard for around $500. Buy the engine and drive it until you have the money to put in good internals such as cam, heads etc etc. If you can afford it, put the good internals into the engine before you put the engine into your car because it will save you hassle later on.