The Small Block Windsor and 5. 0-liter engines are two of the most popular engine designs in the history of Ford technology. and now, RHS(R) has developed an impressive head series to provide Small Block Ford engines with increased airflow and horsepower no porting or modifications needed. RHS(R) Pro Action? Small Block Ford Cylinder Heads include more standard features than any Ford head in the industry, including premium bronze valve guides for extended valve sealing and durability. With a host of runner and chamber sizes to meet various performance needs, these heads are truly the race winner's choice. Designed for Small Block Ford 289-351 Windsor & 5. 0-liter engines; compatible with all OEM & aftermarket componentsSmaller valve package allows usage without piston modificationDual exhaust bolt pattern fits both stock manifold & large tube headersClean Cast Technology? provides better casting quality for minimized airflow restriction & improved airflow efficiencyPit Stop USA offers Racing Head Service Pro Action(TM) Aluminum Racing Cylinder Head - SB Ford - 215cc Intake Runner - 58cc Comb. Chamber - Intake/Exhaust 2.080", 1.600" - Bare 35013 at low everyday prices. Be sure to check out all of our products from Racing Head Service including Racing Head Service Aluminum Heads - Small Block Ford and RHS Aluminum Heads - Small Block Ford.