Engine Kit, GX390, 420cc , +.200 Cast Crank, 88mm Cast Flat-Top Our Price: $321.00 Engine Kit, 218cc for Non-Hemi Predator Our Price: $256.00 Hop Up Kit; GX240, GX270, 9hp OHV; Stage 4 Our Price: $886.00 Hop Up Kit, 208cc DuroMax, Stage 4 Our Price: $518.00 Hop Up Kit; GX340 to GX390, 420 Predator, & 13/15hp OHV; Stage 1 Our Price: $45.81 Header, BSP Pipe with RLV Mini 91 Our Price: $55.37