If you are saying you are gonna spend 3k on just the shortblock then I would look into big bore if you want high hp N/A. obviously big bore 5.4 4v would be the best platform to start with but it will more than ring out your 3k budget on just the shortblock. Another option is a 4.6 big bore or stroker or big bore stroker short block. components should be forged crank,rods,and pistons. And if it's gonna be a N/A motor then flat top pistons so you can get higher compression.