NRHS is Proud to Offer Premium Quality Cylinder Heads from STD Development, Available as a Bolt-On Street Performance Replacement for Your OEM Heads or Custom Configured for Big-Bore and Racing Applications

STD Street Performance Heads for Twin Cam and Evolution

When you're in need of more than an OEM head can provide, it's time to step up to a set of STD heads!

These are super high quality heads made from premium material, designed to withstand the rigors of your hot-rod street project or high compression, high rpm competition applications.

Configuration of the chamber to your piston dome and desired compression ratio is included with these heads at no extra charge. Note that some combinations of piston domes and compression ratio may require excess deck milling which compromises valve to piston clearance as well as manifold fit and may also necessitate shorter or adjustable pushrods. Please call if you're unsure.

STD street performance heads are offered in four different levels of preparation. All heads come standard with 1.94" intake and 1.615" exhaust valves.

STAGE I
This pair of heads includes 175lb. spring kit, steel collars, one piece stainless black nitride coated valves, a completely blended valve job for maximized flow, horsepower & torque.

STAGE II
This pair of heads includes Hurricane premium titanium collars and your choice of .600 or .650 lift spring kit, high flow Hurricane valves, and a completely blended valve job for maximized flow, horsepower & torque.

STAGE III
This pair of heads includes steel collars with 175lb. spring kit, one piece stainless black nitride coated valves and a full porting job for maximum performance, horsepower & torque.

STAGE IV
This pair of heads includes Hurricane premium titanium collars and your choice of .600, .650, or .700 lift springs, high flow Hurricane valves, and a full porting job for maximum performance, horsepower & torque.

STD Heads for Big-Bore and Racing Applications

When going to a big-bore, ideally you want a head made for the larger bore size, otherwise you'll never get everything out of the motor that it's capable of delivering. NRHS can provide STD heads with the chamber enlarged and with the valve angles altered such that larger valves can be used to take advantage of the bigger bore. Other options available include raised ports, oval intake ports, dual carbs, and external head drains. Properly configured, these heads will take your horsepower and torque to a new level that's simply not feasible with OEM heads. We've done many race and street engines with these heads and the results are truly impressive.

This level of head is custom configured to your application specifically. Please call and speak with directly with a performance consultant, we are happy to help you make your project a success.