Engine Kit, GX390, 420cc , +.200 Cast Crank, 88mm Cast Flat-Top Our Price: $321.00 Engine Kit, GX390/420, 440cc, +.200 Billet Crank, 90mm Forged Piston Our Price: $894.00 Engine Kit, GX270, 292cc (+.160) Stroker, R (2 to 1 Gear Box Cranks) Our Price: $519.00 Hop Up Kit; GX240, GX270, 9hp OHV; Stage 4 Our Price: $886.00 Hop Up Kit, Mud Motor Kit with Exhaust, GX200, 212/224 Predator, 6.5 OHV Clone, 208 DuroMax Our Price: $209.00 Header, RLV 3-Stage Pipe for Open & Modified GX200, 6.5 OHV, and 212 Predator Our Price: $38.99