Modified aft edge of L & R lower cowling aft flanges for fit. Fit top cowling and drilled 10 R side holes to flanges. Expanded cowling holes to 15/32". Installed grommets and fasteners to R upper cowl. Rivet R side receptacles. Marked and drilled 10 L side holes to flanges and expanded. Installed grommets and fasteners to L upper cowl. Rivet L side receptacles. 4 holes on L side are too far forward. Will have to move.