PAIR Chevy 350 225 CNC Cylinder heads Assembled Hydraulic Roller, Proline Springs Alloy Angle Plug Small Block Chevy CNC Ported

These are the best Chevy 350 CNC Ported Cylinder Heads. *Pair*

Assembled for Hydraulic Roller, High RPM.

DRP Proline Valve Springs by PAC Racing. 

DETROIT RACING PRODUCTS Cylinder heads. 

Chev 23 Degree DRP Aluminium Cylinder heads

DRP’s Small Block Chevy cylinder heads offer a cylinder head with improved port and combustion chamber designs that result in “Bolt on Horsepower”!

Cylinder Heads play such a critical role in your engine and performance cylinder heads usually come at a significant cost. The DRP range of Cylinder heads are easy on the budget while delivering on performance, precision and quality. These CNC Ported DRP Chevy heads have the ports CNC upgraded while maintaing as cast chambers. These cylinder heads perform out of the box, bolt on and go! These CNC versions are an improvement on the As Cast versions.

DRP have not CNC machined the combustion chambers, because they dont have to. The Chambers are perfect as cast! An added benefit is the combustion chamber stays small, maintaining compression.

Specifications of the Assembled Hydraulic Roller CNC Chevy 350 cylinder heads:

• Valve Springs: DRP Proline High RPM by PAC Racing
  • LS Style, Small OD, Light weight polished springs
  • 160lbs Installed @ 1.800”
  • Rate: 415lbs/in
  • Max Lift: 0.670”
  • Open Pressure: 411 lbs @ 0.600” lift
• Valves: Ferrea 5000 Series.
• Hardware: Comp Cams

Features of the Chevy 350 CNC ported Cylinder heads:

• Angle Spark Plug
• CNC Port Shape, High Torque inlet runners that flow 573hp @ .600" lift
• 228cc Intake runner volume (CNC Ported)
• 88cc Exhaust  (CNC Ported)
• 64cc Chamber size (As Cast)  (these heads can be milled down to 60cc)
• Crisp throttle response. 
• Internal Cast Quality + Thick ( Super Smooth Water Jackets for maximum flow - see our photos of the internal casting) 
• Optimal Spark Plug position. The copies dont have this location. 
• Premium Bronze Valve Guides. 0.570" OD 
• Use Valve Stem Steals: Comp Viton: 518-16   Teflon: 503-16
• Seal Size 0.530" x 11/32
• Hard 355-T6 Aluminium - Race Quality.
• 3 Angle Valve Seats
• Intake Valve size: 2.02" 
• Exhaust Valve size: 1.60"
• Recommended Spark Plugs: 750 reach gasketed 5/8 hex. NGK-BCPR7ES
• Recommended Intake Gaskets: Felpro 1205 std Port or Felpro 1206 for Ported
• Recommended Guide Plates:  DRP-4835-GP
• Valves: Intake: 2.020" x 5.011" Long x 11/32" stem.
• Valves: Exhaust: 1.600" x 5.011" long x 11/32" Stem.
• Intake valve seat can be cut to accommodate a 2.080" Valve diameter.

These heads flow HP all with a 2.02" diameter valve. (can be taken out to 2.080" valve)

593hp @ 0.700" lift

573hp @ 0.600" lift

553hp @ 0.500" lift

Flow Figures*:         

Lift          Intake          Exhaust

200          141             98

300          197             126

400          241             154

450          259             165   

500          269             174    553hp

550          272             182    

600          278             188    573hp

650          284             192   

700          288             197    593hp

* Flown on a Superflow 600 with a 4.030" Bore and a 30° back cut to the intake valve. No pipe on the exhaust.

*Output will be determined by your combination and build quality. 

Have confidence and pride these are quality items Hand Assembled right here in Melbourne Australia.

Exceptional Quality for a Wow factor of a price!