Dart’s Big Chief cylinder heads for big-block Chevys are arguably the most popular cylinder heads in bracket and sportsman drag racing. They do however present a challenge to valvetrain designers due to their aggressive valve locations and pushrod angles that put extreme sideloads on shaft rockers. JESEL solved much of the problem with its “Zero Thrust” upgrade a couple of years ago that located a Torrington needle thrust bearing to absorb the side loads exerted on the rocker.

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JESEL has just released another upgrade for the Dart Big Chief – a one-piece billet stand that securely anchors the shaft rocker system to the head. A simple machine shop milling operation is required to bring all rocker pads down to the same level, but any competent machine shop can easily perform this operation. (JESEL will also do the machine work if you send your cylinder heads to them).

The rockers are CNC machined out of heat-resistant, 7000 Series aluminum, shotpeened for strength and fitted with precision Timken needle bearings that ride on centerless-ground, high-strength steel shafts. These rockers are rated for more than one-inch-lift cams and 1,200 pounds of open spring pressure. Several options are available including .360” or .250”-wide needle nose rollers, several lightening options such as the single-rib MoHawk style, and
JESEL’s exclusive ball adjusters that reduce friction and make the rocker even stronger.

For more information please contact: JESEL Valvetrain Innovation, 1985 Cedarbridge Ave., Lakewood, NJ 08701. Phone 732.901.1800, Fax 732.901.6777, or visit http://www.jesel.com.