Harland Sharp needle bearing, single shaft mount, rockers for Small Block Chrysler are like no other on the market. The only shaft rocker of this style to feature heavy duty needle bearing fulcrums matched with specially heat treated, heavy wall, rocker shafts. Harland Sharp Mopar kits are designed for extreme applications with valve springs up to 1.500 diameter and .900 lift cams. The 7/16-20 x 5/16 ball adjusters are designed for use with the factory style pushrods, length to be determined after you have rockers installed. Harland Sharp SB Mopar kits require taller valves. Approximately .100-.150 are necessary for correct geometry but sometime lash caps can be used.