$650 Stealth heads don't come along every day. I've worked in a machine shop rebuilding cylinder heads for 30+ years and yes, it's not hard to put a ton of money into a set of heads. However, with that being said, if you start with a decent set of 452 heads that already have the induction hardened exhaust seats, it doesn't cost a lot for guides and a decent valve job. It should go without saying that if you're starting with a set of heads that have had 3 or more valve jobs or are rusted hulks, it's going to cost you. The bulk of cast iron heads I've seen are straight and flat, needing only a clean up pass on the surface. If you are milling the heads to up the compression, save your money and buy better pistons. Not everyone is looking to build a 600 horse motor for their cars. In my opinion a factory 440 HP engine IS a respectable engine.