Speed Pro Forged Piston Set 4.350" Bore 1 16 x 1 16 x 3 16" Ring Grooves Plus 12.1 cc Coated Skirt Mopar RB Series (Set of 8) David Clark Features:CNC machined billet aluminum housing EQ TCC294A Features:CNC machined billet aluminum housing and billet aluminum baseWill not accept a vacuum advance canisterMust be used with an MSD Ignition ControlSupplied with an HEI style distributor cap and rotor (accepts Cap A Dapts)O ring seals can be added to modified blocks to improve oil pressure controlSpecial oil tract improves lubrication to the distributor and cam gearNylon pads ensure smooth operation of the advance weightsAdvance weight pins are staked and tig welded to the plateMechanical advance assembly can be locked out for crank trigger systemsAdvance plate and weights are fine blanked from chrome moly steel and QPQ coated for friction reductionPolished steel shaft is QPQ coated and guided by a sealed ball bearing and extra long sintered bushingMaintenance free magnetic pickup and precision reluctor create stable trigger signals throughout the rpm rangeEasy to adjust mechanical advance with supplied springs and stop bushingsNo CARB Exemption Order Number Ford: Custom 64 70 7 L Engine 0006") per set 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