Chevy 350 Engine - Crate This!

On The Dyno
With the new powerplant fired up, we immediately varied the rpm between 1,500 and 3,200 for 20 minutes to make sure the cam, lifters, and piston rings were seated properly. Our first few dyno pulls were made half way through the engine's rpm range to tune for optimum timing and jetting, where we established a total timing advance of 38 degrees with Holley's box-stock HP jetting. Once all the engine vitals were stable we made a series of baseline pulls to come up with a repeatable 315 hp at 5,100 rpm and 351 lb-ft at 3,700 rpm. Both GM and our dyno numbers occurred at the same peak points, showing us that our lack of accessories and use of high-performance dyno headers were perhaps why our baseline numbers were a bit higher than the GMPP ratings. It just goes to show that GMPP doesn't fudge its power numbers to sell engines.

The 650-cfm Holley HP-series...        read full caption The 650-cfm Holley HP-series carburetor and MSD ignition components worked well with our Edelbrock intake manifold. The electric water pump helped ensure that our engine cranked out consistent power numbers.

Before running any hydraulic...        read full caption Before running any hydraulic flat-tappet engine it's a good idea to prelube the oiling system and make sure there's some break-in lube included. We used Comp Cams break-in oil No. 159 and an oil-pump-drive prelube tool.

After making some serious...        read full caption After making some serious torque and horsepower improvements we couldn't wait to see what a little more valve timing would do to our power curve. We swapped out the stamped-steel 1.5:1-ratio factory rockers for a set of Comp Cams Magnum series 1.6:1 roller-tipped pieces and found 12 hp more at the peak rpm point.