434 Stroker Build - W-Engine Revival - Part Two

The stainless valves are swirl-polished and feature 2.19/1.72 head diameters. Stock 348 valves measure 1.94/1.65. Hardened valve seats are included for compatibility with unleaded fuel.

The supplied single valve springs (left) rate 115 pounds on the seat and are rated for flat-tappet cams with up to 0.600 lift. Our Isky solid roller is significantly hotter so the stock springs are replaced with Comp double springs rated 220 pounds on the seat and 545 pounds at 0.650 lift (right). Isky 10-degree moly retainers and locks (PN 200-ST-10) protect against pull-through.

Though our Ross pistons deliver 11.7:1 compression with 0.040-thick Victor-Reinz composite head gaskets (top, PN 1195VC), if we want to drop compression to a pump-gas-friendly 10.5:1, all we need to do is stack the 0.035-thick Innovative Machine steel shim (bottom) between the block and the gasket.

An Isky R-561 solid roller cam extracts peak performance from the free-breathing heads, lofty compression, and extra cubic inches. Specifications are 0.639/0.639 lift, 294/294 advertised duration, 260/260 duration at 0.050 lift on a 112-degree lobe center. Isky solid rollers, dog-bone tie bars, and 3/8-inch moly pushrods move the valves.

The roller cam is located by a Manley solid aluminum thrust button (PN 42146). A Cloyes True Roller double timing set (PN 9-3101) maintains proper cam phasing.

Scott Emley installs the lightweight aluminum heads atop the 434-inch stroked short block. The Edelbrock head bolt kit (PN 8581) features hardened washers and high-grade bolts that torque to 65 ft-lb. Teflon pipe sealant must be used on all threads, as many pass through the deck and into the water jacket.

Big-block Chevy rocker arms fit W heads (stock and Edelbrock), so PRW 1.7 roller rockers (PN 42104-16) fill the bill. Manley lash caps (PN 42104-16) protect the 11/32-inch valve tips from wear.

Edelbrock reconfigured the W's staggered rocker arm stud design so they're both aligned on the same 10-degree tangent from the deck. The goal was to simplify the pushrod guide plates. Valve lash is set at 0.28/0.28 intake/exhaust cold.

W-motor water pumps are much wider than small- or big-block units and used to be quite scarce. Edelbrock's new high-capacity aluminum pump (PN 8858) solves the problem while shaving several pounds.

In the Beach Boys' day, dual quads were as good as it got. Today an LWA/CRW Industries single-plane intake gets the nod. Its removable plenum lid accepts single quads, dual quads, or even a GMC blower.

The bottom of the machined aluminum casting seals the lifter valley and keeps hot oil from affecting the intake charge thanks to divorced runners. Rich Rojeski founded CRW to build cast aluminum parts for Lamar Walden Automotive, including such goodies as never-was Z-11 heads and intake manifolds.

A Holley 950 double-pumper (PN 0-80496-1) feeds the hungry 434 while reworked 21/4-inch Bassett small-block boat headers handle the exhaust. Edelbrock's new four-into-one undercar headers for the 348/409 were not available for testing but are now ready for your project. Building on the no-nonsense theme, the black powdercoat was removed from the Edelbrock cast valve covers (PN 41403) for a rowdy as-cast finish.