Stroke it baby!

You can get some really good power from either a 360 or 5.9L Magnum engine without spending as much as building a 4" stroke properly. In the Magnum's case, you can buy it and drop it in and drive it with stock parts it still makes 300hp. buy parts as you beat on it.

A 360 is going to be your best bang for your buck. Once you raise the compression in a 360 its basically a stroked 340.