Apparel
CHEVY LT1
Valves Valvetrain Components Pushrods Rods Pistons Crankshafts / Rotating Assemblies

RACE SERIES VALVES - learn more about our valves
Manley valves have set the standard for excellence in quality, material and design in the performance world for four decades. Manufactured from proven Race Master materials, Manley valves feature chrome stems, hard tips, fully machined surfaces and swirl polished radii. Many applications are Pro Flow design for maximum air flow.
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
12345-8 Exh. 1.590 .3136 Stock 5.205 .160 25° x 7/16" .075 .100 18° Dish 97
12348-8* Int. 2.120 .3133 Stock 5.253 .170 Pro Flo 12° x 3/8" .050 .070 7° Dish 124
* Valve #12348-8 has a back cut of .075" x 30°

PRO FLO SEVERE DUTY VALVES / EXTREME DUTY VALVES - learn more about our valves
Manley valves have set the standard for excellence in quality, material and design in the performance world for four decades. Manufactured from our proven Severe Duty and XtremeAlloy materials providing the ultimate in strength and durability. Manley valves feature chrome stems, hard tips, fully machined surfaces and swirl polished radii. The intakes utilize our Severe Duty material, the best available, and are the Pro Flo design for maximum air flow. The Extreme Duty exhausts are made from our top of the line XtremeAlloy exhaust material, the best in the market making it ideally suited for forced induction and nitrous applications.
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
  PRO FLO / SEVERE DUTY
12347-8 Exh. 1.590 .3136 Stock 5.205 .160 25° x 7/16" .075 .100 18° Dish 97
12352-8* Int. 2.120 .3133 Stock 5.253 .170 Pro Flo 12° x 3/8" .050 .070 7° Dish 124
  EXTREME DUTY
12349-8 Exh. 1.590 .3136 Stock 5.205 .160 25° x 7/16" .075 .100 18° Dish 97
* Valve #12352-8 has a back cut of .075" x 30°
© 2020 Manley Performance Products, Inc.
[email protected]  |  Terms and Conditions  |  Prop 65