When you see what people are running on their engines says a lot. I've been around a lot of guys who have built engines and not a one of them have used procomp heads or other Chinese cylinder heads because of poor quality issues. I've built a few engines over the years put always had to use the factory heads due to budget reasons. The only guys I hear of running speedmaster or other import cylinder heads are guys on car forums, I know guy's who have built fast cars and they always ran top notch cylinder heads and pistons, etc. I may not be as experienced as some on here, but I do know my way around engines.