How easy to get 500 horsepower w/ stock stroke 440?

A couple thoughts based on your comments. EFI will help with the streetability. Good call there. As will a modern engine management system (assumed on that one that it's part of the EFi package). But - fuel economy has to do with efficiency at (usually) a narrower rpm range because its miles per gallon. If you want big torque, and not have to work the engine as hard (meaning turn a higher rpm to reach that output), then bigger is better, and the result will be more efficient at a lighter throttle. I think stamped rockers are a mistake with any type of roller lifter. The static compression will be whatever depending on your hard parts choices and setup. Personally I like dished pistons, smaller chambers, and I bring the pistons proud of the deck - not flush. Reconditioned rods will work with good bolts and pin bushings, but new rods will be stronger for a little more cash. Just make sure you have the new ones looked at unless you spend the bigger dollars. Cast crank will work, but will be an internal balance challenge (read that as probably will need a little more $$ to internally balance). But you won't break it.