if it was me i would go with a 351 that way i could keep it efi(assuming you have a 5.0) so it would be easy to do. you could go over to carb so you don't have to deal with the limitation of speed density though. a 351 built right can put out some horsepower. if you want a power house then you could go with a 460 and just upgrade the front suspension, to compensate for the added weight.
A 351 sounds good. I'm not looking for something so huge I need to beef up the suspension alot, but thanks for that info. How do I go about finding out about retail on an engine and where to get it? What should I look for? Thanks for putting up with my stupidity when it comes to this stuff.