Performance is a complicated subject. It's not a matter of choosing the largest cylinder heads or the longest duration cam. Each total combination has its own requirements, depending on a multitude of related factors. SD Performance has the equipment and the hands-on experience to help our customers attain their individual objectives. We know how to match cylinder heads, manifolds, carburetors and camshafts to maximize the performance of your specific combination. All port work includes a printout from our state of the art computerized SUPERFLOW 600 flowbench. We test velocity on all ports to assure that the port is efficiently shaped for a particular combination. Our prices are competitive and our combinations work. Give us a call and we'll put you ahead--way ahead, with the "right" stuff the first time.

See how your heads stack up against proven performers

Mo Discount - Flow Testing Special

• Includes two heads, 8 intake and 8 exhaust ports.
• All ports flowed on our Fully Computerized State of the Art Superflow 600 Flow Bench
• Test Airflow at any lift at any pressure
• Port Velocity at any lift at any pressure

P   R   I   C   I   N   G

With the exhaust crossover open, the full effect of exhaust scavenging cannot be obtained, inhibiting power potential

For street use, a single 3/8" hole allows the customer to utilize a choke while still improving performance by reducing manifold heat from 4 cyliners to only 2