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
PRO1 24 275cc Oval Port

PRO1 24° 275cc Oval Port

Categories: , ,


For street performance, mild bracket racing and marine. Under 6,800 RPM, under 500 cubic inches. Excellent mid-range torque and power, good for heavier vehicles.

A new high velocity oval port design makes this head an ideal choice for street cars and trucks. The PRO1’s race proven features include rolled valve angles, improved spark plug location, extra long intake valves, raised exhaust ports, and fast burn chambers.

Long wearing Bronze valve guides, screw-in studs, multi-angle intake seats with hardened, radiused exhaust seats are standard. Best of all, our precision cast ports produce outstanding airflow without time consuming porting.

Assemblies include Stainless Steel valves, premium springs, locks, retainers, guide plates and seals.

Heads are sold individually.


Material: RMR Cast Aluminum Alloy

Valve Angle: 24°

Intake Port Volume: 275cc

Intake Valve: 2.190”/2.250”

Exhaust Valve: 1.880”

Chamber Volume: 110 or 121cc

Intake Port Shape: Oval

Exhaust Port Location: .300” raised

Dart Marine PRO1 cylinder heads

Features an exclusive chromate surface finish to inhibit corrosion and extend the life of the head.

Fitted with Inconel exhaust valves to withstand the extended running time and temperatures typical of marine usage.

PRO1 24° 275cc – Aluminum (w/ 2.190” Intake Valve)

19000070 – Bare Head

19000171 – 1.550” Single Springs for Hydraulic Flat Tappet Cam .660”

19000172 – 1.550” Dual Springs for Solid Roller .690”

PRO1 24° 275cc – Aluminum (w/ 2.250” Intake Valve)

19000010 – Bare Head

19000111 – 1.550” Single Springs for Hydraulic Flat Tappet Cam .660”

19000112 – 1.550” Dual Springs for Hydraulic Solid Roller .690”

19000116 – 1.625” Dual Springs for Solid Roller Cam .850”

PRO1 24° 275cc – Aluminum (Marine Heads w/ 2.190” Intake Valve)

19000070M – Bare Head

19000172M – 1.550” Dual Springs for Hydraulic Roller Cam .690”

PRO1 24° 275cc – Aluminum (Marine Heads w/ 2.250” Intake Valve)

19000010M – Bare Head

19000112M – 1.550” Dual Springs for Hydraulic Roller Cam .690”

PRO1 275 Tech Sheet – H37