Hotrod magazine LA BUILD VERSUS LS

Valley Performance started with an early Magnum 360 block that was reinforced with Hard Blok in the water jackets and underwent a number of modifications for windage-reducing oil control. Valley Performance also had a splayed four-bolt main caps made for it to provide extra support for the mains. The cylinder was bored out to 4.100 inches to unshroud the valves.

Inside the block is an Eagle forged crankshaft the slightly reduces the stroke from 3.580 inches to 3.556 inches. The rods and pistons include Eagle 6.250-inch H-beam rods and custom Ross forged pistons that contribute to an 11.66:1 compression ratio. The camshaft is a Bullet roller unit with 0.775/0.774-inch lift and 255/265 degrees duration

The relatively new Edelbrock Victor cylinder head is credited with helping push this small block project to the winner’s circle. They offer large, 225cc intake ports, raised exhaust ports and a revised 16-degree valve angle (stock is 18 degrees). Out of the box, the head is good for about 345 cfm on the intake side and 237 cfm through the exhaust ports.

Valley Performance enhanced airflow in the new heads by opening up the walls a bit to eliminate the pushrod inch, along with a little guide work, resulting in a strong 372 cfm at 28 inches of water. Note, too, the 5/16-inch bolt at the upper left of the stock bolthole. It was to bolt up the W2-style tunnel ram intake manifold.