i just baught a set of 3917291 heads.. they've been milled to make it 60cc chamber with screw in studs,guides and good springs and keepers.. now i know a bit about this process i was just wondering if theres anything i should know or check before i slap these on.. they have been done over recently and are pretty clean.. they guy had them on flat tops, i'm running dished pistons.. he said they'd bolt on...i just wanna know if theres anything different with milled heads???