Engine Kit, GX390/420, 440cc, +.200 Cast Crank, 90mm Cast Piston Our Price: $313.00 Hop Up Kit, 460cc (10-Bolt) Engines Our Price: $1,285.00 Engine Kit, 236cc for Tillotson 72mm Block, Stroker Kit Our Price: $229.00 Hop Up Kit, 224cc Predator, Stage 4 Our Price: $506.00 Engine Kit, 202cc, 2.186 (+.060) Stroker, 2.68 Bore, Clone Crank & Piston Our Price: $226.00 Hop Up Kit, 440 Duromax, Mud Motor Kit, Stage 4 Our Price: $1,281.00