alright dude... this right here is the ultimate swap and not too expensive either! i am doing one now and building another one up... a lincoln MARK VIII engine (it has a factory aluminum block that can withstand excess of 1500 hp its a teksid block) it is a dual cam engine that bolts directly in and swap out the crank for a 8 bolt cobra crank(about 2-4 hundred bucks) a set of decent rods and cobra fordged pistons. that with stock mark 8 heads made 365 hp at crank at 6800 rpm. a set of stock cobra heads will put you around 395 hp at 5900 rpm. i did this whole engine for a total cost of $2600 (600 for engine, 870 for cobra heads, 350 for cobra crank new and 730 for manley rods and cobra pistons)