Pump Gas Kits Designed to give the most HP per cc based on running pump fuels. Each kit comes with AMR/Diamond Racing Piston kit * 2618 Alloy forged pistons (12-12.5:1 compression depending on application) * H-13 wrist pins * Total Seal Rings * Circlips * .185" deep valve pockets accept up to +1.5 valves _______________________________________________________ AMR/Web Camshafts  *Hardwelded on your core  *reground to AMR specs (X1, or X2 with pump fuel) _______________________________________________________ AMR/Kibblewhite Valve Springs * Dual Spring * Higher open and closed pressures to maintain high RPM stability * More valve travel _______________________________________________________ AMR Race Kits Same as above with 12.5-14:1 compression, depending on application Pistons have anti friction skirt coating, and gas porting Valve pockets are .200" deep, and accept up to +4 valves AMR/Web cams (X4, and X5's) AMR Kibblewhite Dual Valve springs AMR/Web Hardwelded Rocker Arms The race kits are best suited for engines with race heads, high flowing exhaust, and large carburetors/throttle bodies.