305 Chevy Small-Block Engine Build - 305 Chevy

The Vortec heads were decked 0.045-inch to yield 55cc chambers, then installed with Fel-Pro's 0.015-inch-compressed-thickness head gaskets (PN 1094) to achieve a bit over 10.0:1 compression. The steel-shim gasket has a precision rubber coating-for long-term use, install them with sealant.

The Vortec heads were decked 0.045-inch to yield 55cc chambers, then installed with Fel-Pr

Another issue with the 305 S/R Torquer heads is that the valve angles are altered to assure no valve-to-cylinder-wall clearance problems. That may mean that larger 2.02/1.60 valves can be installed-but there's a heavy emphasis on the may, since we haven't tried it. The heads come complete with 1.94-/1.50-inch valves and valvesprings, and have screw-in studs, which the Vortec heads don't. World's 305 heads use conventional valvesprings; the Vortec units require new ovate-wire springs in a smaller diameter.

We tested the World 305 heads on our dyno mule along with the standard Victor Jr. intake, the Holley 750, and the Comp Xtreme Energy 262 cam. In this configuration, we made 297.6 hp at 5,500 rpm and 308 lb-ft at 3,900 rpm-healthy for a little engine. These numbers can't be compared fairly to the 325-horse/316 lb-ft numbers with the Vortec heads because the intake-manifold design was slightly different.

For more information, contact World Products, Dept. CC, 35330 Stanley Dr., Sterling Heights, MI 48312-2654, 810/939-9628, www.goracing.com/world

What'll It Cost Me?
The total cost of the Vortec cylinder-head package depends on your small-block's vintage. If you already have '87-and-up center-bolt valve covers and guided rocker arms, you can put this package together for about $1,575. Figure on spending up to $125 more if you need the extra parts and want to buy them new. You could save money scoring good late-model parts from a salvage yard.