Dart Machinery, LTD. stands behind each product we manufacture 100%. Each component undergoes a detailed manufacturing process that involves the hundreds of calculated and precision steps to ensure the finest quality possible.

Warning This product contains chemicals known to the State of California to cause cancer and reproductive harm. www.P65Warnings.ca.gov
Big Chief II 11 512cc CNC Port

Big Chief II 11° 555cc CNC



Maximum Top Sportsman, Top Dragster, Pro Mod and Pro Street competition. Excellent with alcohol and nitrous, over 7,000 RPM, over 500 cubic inches.

The latest Big Chief evolution with an 11° valve angle, this head features a multitude of revisions: relocated valve centers, relocated port cores, and a redesigned valve train for increased power and reliability.

With our sophisticated CNC machining programs, we can tailor a pair of Big Chief II heads to fit your exact engine combination.

Copper seats are standard and assemblies come with Titanium valves. Option for 2.500″/1.850″ intake/exhaust valves.

Heads are sold individually.


Material: RMR Cast Aluminum Alloy

Valve Angle: 11°

Intake Port Volume: 555cc CNC

Intake Valve: 2.470”/2.500”

Exhaust Valve: 1.800”/1.850”

Chamber Volume: 56-90cc

Intake Port Shape: Oval

Port Location: Spread port

Big Chief II 11° 555cc CNC – Aluminum

18500000 – Bare Head No Porting

18575070 – Bare Head Full Port 512cc 2.470/1.800 4.600

18575179 – Assembly Full Port 512cc 2.470/1.800 1.650T 4.600

Big Chief II 11º Tech Sheet – H54