Speed Pro Speed Pro Piston Forged 4.350" Bore 5/64 x 5/64 x 3/16" Ring Grooves - Minus 7.0 cc RG20001XS producing approximately 3

producing approximately 3

NOTE: The 20-121 is not designed for use with some early model Holley carbs

Meets NSRA Safety Requirements

Stores 100 Chassis Setups

Dana 60 / 61

Speed Pro Speed Pro Piston Forged 4.350" Bore 5/64 x 5/64 x 3/16" Ring Grooves - Minus 7.0 cc RG20001XS producing approximately 3Fully 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.