Stroker 340>416 Build Advice

Thanks for the response so far! To answer some of the questions:
Weight of the car is unknown but Id imagine pretty close to stock as not a whole lot has been done to customize it.
Gearing right now it has a sure grip 3.73 741 case which I want to get a 742/489 case with probably 3.55 to get closer to highway speeds at not a ridiculous rpm and make it stronger for the higher hp engine.
Elevation is between 1kft-3.5kft
As for hp after reading other posts Id be happy with 450-500hp I dont really intend on dragging much or doing cannonball runs haha