Heads are stock 96 heads that have been ported and polished with biger intake valves and better flowing exhaust valves. Work done by Alefs HD in Wichta. I have both SE255 and Headquater 575 Cams SE are HD. Heads with .030 head gasket will be 10.5 CR with .060 gasket will be 9.8 CR. These parts have about 8,000 miles on them.