Hotrod magazine LA BUILD VERSUS LS

Thermal-coated exhaust ports help keep in heat and move air faster. Valley Performance says the ports flowed well stock, but they nonetheless opened the bowls and worked on the short-turn radius, bumping flow to 265 cfm.

Out of the box, the Edelbrock Victor heads have 58cc combustion chambers, complemented with Valley’s insertion of 2.175-inch hollow-stem intake valves and 1.600-inch exhaust valves. Valley Performance blended the valve seats and combustion chamber area to enhance airflow, ending up with 61.5cc chambers.

For oil control, the oil drains in the heads were plugged, forcing the oil to exit externally through the front and rear of the head casting and preventing it from draining back into the lifter valley.

Moving up to the valvetrain is a set of PAC Racing Springs dual-coil springs with titanium retainers. Specs include an installed height of 1.88 inches and a 675-pound spring rate.

The pushrods are strong, 3/8-inch-diameter with 0.120-inch walls, from Smith Brothers.

Hughes Engines supplied the 1.7-ratio roller rocker arm assemblies, which have been cryogenically treated to enhance strength. They’re actually big block Wedge-style assemblies to accommodate the offset that comes with the heads’ 0.600-inch-longer intake valves.