Credit the Holley Dominator EFI system for the ability to accept and tune all of the different cam profiles.
While we were on factory cams, we decided that in addition to the peak power gains, it would be interesting to document things like idle vacuum, cranking compression, and average power and torque gains lower in the rev range.
Here is a common question among LS engine enthusiasts: My buddy, Joe, just bought a new cam for his 6.0L and wants to get rid of his factory LQ9 cam. We wrestled with valvesprings, cams sensors, and differing bolt patterns to get all these cams into the engine and on the pump. The 5.3L used for testing was bone stock, which required at least a valvespring upgrade for the high-lift LS9 and LS7 cams.
Is that a good cam for the 5.3L in my truck, for my 240SX drift car, or the LS engine I am swapping into my second-gen Camaro? The result is a guide that will help you select the best OE GM cam for your 5.3L build. These cams can be had for pennies on the dollar and benefit from millions of dollars spent on the research and development of idle quality, longevity, and fuel mileage. Even the LS2, LS3, and LS6 cams offered more lift than the factory 5.3L (LM7) springs could support, to say nothing of limiting rpm potential.
LS Engine Designation: LS1 (’98–’00)The odd thing about the LS2 test was that this was the only factory cam with which we experienced valve float.
Run on the high-mileage 5.3L, the stock 5.3L cam produced peak numbers of 353 hp at 5,200 rpm and 384 lb-ft of torque at 4,300 rpm.
It is interesting to note that the same cam was used on the smaller LR4 4.8L, and that combination (same heads, cam, and intake) makes peak power 300 rpm higher.
We wanted to know how an aftermarket cam of equal (or near-equal) duration compared with the stock stuff. Check out the results to see how your favorite cam compared with the factory LM7.
Baseline: 5.3L LM7 Cam Being such a diminutive factory cam, it is not surprising that power fell off so rapidly past 5,500 rpm.