Speed Pro Speed Pro Piston Forged 4.280" Bore 5/64 x 5/64 x 3/16" Ring Grooves - Plus 25.7 cc 110015 is what these lifters have

is what these lifters have been manufactured from since their original design

1966-1966 GMC G1000 Series

2000-2004 Dodge Dakota

1957 Ford Country Squire Liter- 5

This dust cap is used to prevent debris from collecting in an exposed interface or analog connection

Speed Pro Speed Pro Piston Forged 4.280" Bore 5/64 x 5/64 x 3/16" Ring Grooves - Plus 25.7 cc 110015 is what these lifters haveFully 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.