Stud Kit, Head: GX200, 6.5 OHV Clone, & 212 Predator Our Price: $20.68 Hop Up Kit, 420 Predator OHV & 13/15hp Clone, Stage 4 Our Price: $1,149.00 Engine Kit, GX390/420, 420cc, +.200 Billet Crank, 88mm Forged Piston Our Price: $923.00 Hop Up Kit, 440 Duromax, Mud Motor Kit, Stage 4 Our Price: $1,276.00 Hop Up Kit, Mud Motor Kit with Exhaust, GX200, 212/224 Predator, 6.5 OHV Clone, 208 DuroMax Our Price: $207.00 Hop Up Kit, GX390 & 13/15hp OHV, Stage 3 Our Price: $406.00