PRODUCT DESCRIPTION
Fits: Mopar Big Block B
Eng. Disp. In. 383
Eng. Disp Liters 6.3
Year Range 1931-1973
Bore (in) 4.25
Bore (mm) 108
Stroke (in) 3.38
Stroke (mm) 85.9
Oversized Yes
Ring Pack 5/64, 5/64, 3/16
Top Land .275
Pin Number 1.094x300K
Pin Type Press or Floating
Pin Diameter (in) 1.094
Pin Diameter (mm) 27.8
Lock PRF116-3
Compression Height IN 1.908
Compression Height MM 48.5
Crown (cc) +8cc
Alloy 390
Compression Ratio 72-9.8, 80-9.1, 84-8.8, 88-8.5
KB Performance hypereutectic pistons are made from 390 aluminum alloy and heat-treated to T6 standards, which makes them 30 percent stronger than ordinary untreated hypereutectics. Their 100 percent CNC-machined crowns, high upper compression-ring location, gas-accumulator groove, drilled oil returns, and spiral-lock retainer grooves make these pistons outstanding for performance applications. They have a lightweight, rigid-rib skirt design that stabilizes the piston in the bore. All of this adds up to pistons that fit tighter than forged types, provide improved oil control, reduce blow-by, increase ring life, eliminate cold start-up knocking, and won't cost you an arm and a leg! Thousands of models are available—find the set and options designed for your vehicle and engine application.
