Apparel
CHEVY 5.3L LS/L83
Valves Pistons Crankshafts / Rotating Assemblies

Race Flo / Race Master & Pro Flo / Severe Duty Valves
  • Chrome Stems and Hard Tips
  • Intakes are "Pro Flo" for Improved Flow
  • Swirl Polished and Machined
  • O.E. Style Radius Keeper Grooves
Part No. Type Head Diameter Stem Diameter Installed Height O/A Length Tip Length Underhead Angle/Radius Margin Seat Width Top of Head Wgt/Grams
  RACE FLO / RACE MASTER VALVES
12359-8 Exh. 1.560 .3136 Stock 5.208 .160 25 x 7/16" .065 .110 18 TBA
12356-8* Int. 1.930 .3133 Stock 5.232 .160 Pro Flo 12 x 3/8" .050 .100 7 TBA
  * Valves 12356 and 12358 have a back cut of .050" x 30

PRO FLO SEVERE DUTY VALVES / EXTREME DUTY VALVES
  • XH-432 XtremeAlloy Material
  • Swirl Polished and Machined
  • Chrome Stems and Hard Tips
  • O.E. Style Radius Keeper Grooves
Part No. Type Head Diameter Stem Diameter Installed Height O/A Length Tip Length Underhead Angle/Radius Margin Seat Width Top of Head Wgt/Grams
  Chevy Small Block 5.3L LS/L83 2014-Up - Severe Duty
12361-8 Exh. 1.560 .3136 Stock 5.208 .160 25 x 7/16" .065 .110 18 TBA
12358-8* Int. 1.930 .3133 Stock 5.232 .160 Pro Flo 12 x 3/8" .050 .100 7 TBA
  Chevy Small Block 5.3L LS/L83 2014-Up - Extreme Duty
12363-8 Exh. 1.560 .3136 Stock 5.208 .160 25 x 7/16" .065 .110 18 TBA
  * Valves 12356 and 12358 have a back cut of .050" x 30
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