12. Though equipped from the factory with partial roller rockers (trunion only), these full roller rockers from Comp Cams offer roller tips and trunions to further reduce friction. The 1.8:1 Comp roller rockers also increased the valve lift to over 0.600 lift. Luckily our TEA heads came with valvesprings that would accept the higher lift and offer the required valve control. The rockers and lightweight oil increased the power output of the 5.3L to 494 hp and 447 lb-ft of torque.