Speed Pro Speed Pro Piston Forged 4.030" Bore 5/64 x 5/64 x 3/16" Ring Grooves - Minus 2.7 cc 931117 HEI owners now have a

HEI owners now have a choice to replace their stock coil with the MSD High Energy Unitized Coil for GM HEI Distributors

Includes roller bearing as well as a 6-degree advance/retard

Ultra lightweight and strong

racing flywheels

5/16" and 3/8" fasteners for most AMC

Speed Pro Speed Pro Piston Forged 4.030" Bore 5/64 x 5/64 x 3/16" Ring Grooves - Minus 2.7 cc 931117 HEI owners now have aFully updated skirt profiles Exclusive DUROSHIELD skirt coating. DUROSHIELD provides scuff resistance, reduced bore clearances and enhanced ring sealing. SPEED PRO POWERFORGED pistons are built to stringent specifications with a precision CNC machined dome and skirts and microfinished ring grooves. The manufacturing process ensures that piston weights within a boxed set will not vary more than 4 grams and that skirt sizes are matched to within 0.