it is only 1mm half a moon more clearance on pocket. Zoran Vujasinovic Twin Works Factory 775-786-4881 www.twfracing.com ----- Original Message ----- From: "Steve Robertson" <srobertson at ssimicro.com> > Because these are Busa pistons the valve pockets would be > bigger to accomodate the larger Busa valves but other than that > is there any reason they shouldn't work?