Use pulldowns above to build out your head. The BC core exchange program works three ways: 1) Buy one of BC's new heads outright, no exchange. 2) Send a new head in for even exchange for one of BC's new "in-stock" heads. 3) Send a used head in, receive that same head back. BC only accepts new, never-been ran Yamaha heads (#2HC-11101-09-00) cylinder heads as new core exchanges. BC uses only new heads for all new even...