I have a set that Iam putting on my engine now, box stock intake flows 237cfm at .500 lift and exhaust is 199 cfm with very very minor porting on the exhaust side. These are the heads that were on my car when I bought it which is why Iam using them. Would I buy them if I started out with nothing, maybe not. They are a good set of heads, though they're are better ones. Comparing TFS twisted wedge heads to these for example, the TW heads flow a tiny bit more and are alum which are two advantages but cost about $300 more. All depends on your budget and what your looking to do. BTW I have the world product senior heads which are the exact same thing as the heads your talking about if that makes a difference. Good luck