Hitman 12 Degree Big Block Chevy Cylinder HeadsRace Winning Performance out of the box...
184 Series 12 Degree Hitman BBC Heads
The Hitman BBC 12º Spreadport takes the guess work out of trying to find the right cylinder head for the most power. Based on Pro-Stock technology, the Hitman offers an out-of-the-box port design that allows any racer or engine builder to have an efficient, high velocity airflow cylinder head within their grasp. Providing you with power over your opponents.
The Hitman Series cylinder heads feature a heart shaped combustion chamber, an oval-shaped port design that is available as a proprietary PRECISION As-Cast or Fully CNC version, and the unmistakable Pro-Filer casting quality.
Air Flow Chart
Note: Flow rates may vary for any number of circumstances due to valve job, valves, the flow bench used, test parameters, etc.
Hitman 12 Degree BBC Racing Cylinder Heads
Material: Aerospace Specification, A356 Aluminum Alloy (Primary Virgin Ingot)
Valve Angle: 12 Degree
Intake Port Volume and Shape: Spreadport Location Oval-Shaped, PRECISION As-Cast 415cc & 470cc
Exhaust Valve: 1.850-1.880" - 6.800 long (2.200 Install)
Intake Valve: 2.400"-2.450" - 6.800 long (2.200 Install)
Valve Spring Pocket: Maximum of 1.655 (no deeper) Combustion Chamber: Heart-Shaped, As-Cast/CNC - 60cc (CNC 72cc & 74cc Power Adder)
Milling: .005 per cc flat milling, .007 per cc angle milling
Deck Thickness: 1/2" deck for Nitrous and Blown applications
Spark Plugs: Revised Location to improve flame travel. Uses Gasketed 3/4" Reach Plugs such as NGK R5671-7 Series
Valve Train: - Uses T&D or Jessel Shaft Mounted Rocker Systems
Bore Spacing: - 4.840 (Standard Big Block)
Valve Guides: Manganese Bronze to assist in extending valve life
Valve Seats: Copper Alloy
Intake Port Design: Pro-Stock Modified Oval Port
Valve Covers - Pro-Filer PN 190
Rockers - Shaft rockers (T & D, Jesel)
Engine Size Recommendation:565+ cid / 9000 RPM
Application: High Performance (i.e. Street/Strip/Marine)