I'm getting ready to build up my 2015 focus. I'm looking for convex pistons because I want to increase compression. I don't know where to look for good reliable performance parts. If there aren't any places that sell convex piston heads, then where can I find a place that sells head gaskets that are thinner than OEM? I know that's a way to increase compression. I'd rather go with new forged pistons though, as eventually I want to slap on a turbo.