Big-Block 502 ci 1. COMP 1.7:1 Ultra Gold roller rockers are CNC-machined to withstand extremely aggressive spring pressures and maintain accurate rocker arm ratios. 2. KB flat-top hypereutectic pistons for 4.500-inch bores are lightweight with rigid-rib skirt designs, which stabilize the piston in the bore. The pistons are also 390 alloy and heat-treated to T6 standards. 3. Proform-fabricated (clear) aluminum valve covers weigh just less than 1.5 pounds each and include recessed Bow Tie and Chevrolet emblems inlaid with classic Chevy Red. 4. The Weiand Stealth (oval port) dual-plane intake manifold has long separated runners for increased torque and makes power from idle up to 6,000 rpm. 5. The MSD 6AL-2 ignition box includes a new housing with digital controls. Rev control adjustments are made via four rotary dials in 100-rpm increments. It also offers higher output, with up to 135mJ and 535 V.