The Jp Chevy 350 Part 2

The GM Performance 290hp 350 crate engine we used proved itself as durable as an anvil. We mercilessly beat it with almost two hundred full-throttle, full-load dyno pulls up to 6,500rpm, and a couple up to nearly 7,000rpm. And it held. As for our camshaft selection, we'll admit that the Lunati Voodoo 268 grind is a bit gnarly for our cylinder heads. Even with our Lunati PN 74818 springs set up to deliver a burly 155lbs-seat and 330lbs-open spring pressures, we still ran into some valvetrain harmonic issues between 5,300 and 6,000rpm. This caused a dip in the power levels right where our peak horsepower would've been found. Ideally, if we were to do this over again, we'd probably select a Voodoo cam with a shorter 219/227 duration @ 0.050 and .468/.489-inch lift (PN 60102), or even one of Lunati's new Street/Strip cams with a less-aggressive lobe profile offering 223/231 duration @ 0.050 and .463/.485 lift (PN 301A9LUN). Either probably wouldn't cost us much (if any) top end power, and would serve to fatten up the torque curve a bit.

Parts List
Want to duplicate our combo? Even though we used a solid and dependable 290hp 350 crate engine and brand-new Vortec heads from GM Performance Parts as our base for this buildup, you could theoretically substitute a decent $100 junkyard 350 shortblock from any '70s-'90s GM car or truck, a set of $180 Vortec heads from the boneyard, and use cheap stock valve covers and fasteners where applicable to duplicate this combo for less than $1,250. Prices were found online as of press time through Pace Performance or Summit Racing. Items marked with an asterisk are optional, meaning stock parts can be substituted.

Test 1: Baseline GMPP 290hp 350 crate engine, GMPP 222/222@0.050, .450/.460 lift camshaft, Weiand Action Plus manifold, Holley 4779 double-pumper carb, 34 degrees ignition timing, 13/4-inch long-tube headers

Test 2: Lunati Voodoo 227/233 @ 0.050, .489/.504 camshaft, Weiand Air Strike Vortec intake, 1/2-inch phenolic carb spacer, Holley 4779 Double Pumper carb, 36 degrees ignition timing, 13/4-inch long-tube headers

Test 3: Same as Test 2 but with Lunati 1.5:1 roller rockers

Test 4: Same as Test 3, but with Professional Products Hurricane Vortec intake manifold, 1/2-inch phenolic spacer, 37 degrees ignition timing Peak Values are in bold.