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GM Performance Parts 350 H.O. Crate Engine - Project Humble Pie, Part II

Bigger Cams and 400 hp From the 350 H.O.

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Power Results

Test 1 is the best overall power the 350 H.O. made from last month's tests. This configuration included an Edelbrock Performer RPM Air Gap manifold, Holley 750-cfm 0-4779 mechanical secondary carburetor, Hedman 15/8-inch headers, and Borla Pro XS 2 1/3-inch muffled exhaust. Idle vacuum measured 16.5 inches at 850 rpm.

Test 2 charts the results from the Xtreme Energy 268 hydraulic flat-tappet cam. While most longer-duration cams usually sacrifice torque at the bottom to gain peak hp increases, this combination improved everywhere over the smaller stock cam. The 268 cam also extended the power up to 6,000 rpm where the smaller cam fell off radically after 5,600 creating a wider 1,400-rpm power band between 3,800 and 5,400. Idle vacuum measured 14 inches at 900 rpm.

Test 3 illustrates the advantages of a hydraulic roller camshaft with its more aggressive lift curve. The roller offers shorter duration at 0.050 yet makes significantly more power than the flat-tappet cam making an honest 400-plus hp with stock port Vortec iron heads. This mild cam makes for a great everyday driver combination with 15 inches of vacuum at idle at 900 rpm.

Parts List

All prices were taken from GM Performance Parts dealer Scoggin-Dickey Parts Center in Lubbock, Texas. We've listed a few other GM Performance Parts dealers that carry these parts. We've also listed some parts like the roller lifters and the valvesprings part numbers separately in case you need separate parts. Keep in mind that the overall Hot cam kit comes with the cam, rocker arms, springs, retainers, keepers, and locks. All you have to add are the roller lifters and the pushrods. The Comp Cams prices were pulled from All prices are accurate for December 1, 2003.

Burt Greenwald Chevrolet
1490 Wooster Ave.
OH  44320
Pace Performance
COMP Cams Sallee Chevrolet
OR  97862
Friendly Chevrolet
MN  55432
Scoggin-Dickey Parts Center
GM Performance Parts
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