5b. The heads featured 200cc intake ports, 64cc combustion chambers, and had 2.02-inch intake and 1.60-inch diameter exhaust valves; a good balance between air/fuel flow and velocity. Continuing with the premise of having a streetable power curve, a Comp Cams hydraulic roller (PN 12-467-8) was used. A set of Manley one-piece chrome moly pushrods connected the Comp hydraulic roller lifters to the Comp 1.6 aluminum roller rockers. This gave the engine a net lift of 0.612-inch at the valve, with a duration of 248 degrees (intake) and 255 degrees (exhaust) at .050-inch with zero lash.