I almost bought a set of the Pro comp heads off ebay as the prices are hard to beat but after porting a set of Chevy Pro comps this week its not gonna happen. The quality of the aluminum between them and Edelbrocks is like night and day. You can feel the difference in your hands and ears when grinding. The seats look like they are begging to fall out and the finish on these heads are terrible. DO NOT plan on running these ever out of the box.