Original Nailhead rockers only had an effective ratio of 1.4:1 as opposed to their advertised ratio of 1.6:1, which greatly reduced the camshaft’s effectiveness. Achieving a more respectable ratio through a better designed rocker, such as our 1.60:1 roller rockers, makes incredible power differences. Results of 20+ hp on stock combination's and 40+ on higher performance combination's can be expected.

Years of development work have gone into this roller rocker design.Making a high quality rocker that is strong, adjustable, lightweight and increases performance was no easy task for the 401 and 425 Nailhead engines. In the past, cheap cast adjustable rockers just did not hold up. More recent rocker designs were heavy and do not use any type of bearing on the shaft. Those heavier designs demand even more from an already tasked valve spring and contribute to the Nailhead’s low RPM range. Lack of roller bearings at the fulcrum not only limited the life span of the rocker,but they also negate the low friction benefits normally enjoyed by using a roller rocker. Higher technology manufacturing and materials have been enlisted to bring your Nailhead into the 21st century, not just keep it in the 20th century! CNC machined bodies, hardened lightweight adjusters,composite spacers and reduced diameter shafts along with high speed tool bearings get the job done. This rocker design will not just improve existing combination's, but will open the door to many more combination's. The least of which will be solid grind camshafts. They come fully assembled with rockers, gun drilled shafts, billet stands, nylon spacers & ARP hardware. Converting to “pushrod” oiling is not required but is easily done by using TA 1405 lifters and TA 1423 series pushrods (which also reduce valve train weight). We also have higher performance valve springs to accommodate the extra valve lift,  Works with stamped steel valve covers. Does not work with original or reproduction “BUICK” aluminum valve covers.

Because of the additional valve lift, piston to valve & spring coil bind MUST be checked!