LS3 Camshaft Upgrade - Sticks With Stones

The stock GM cam falls on the mild side with duration numbers (at 0.050) of 204/211 and lift of 0.551/0.525 on a 117 LSA. After crunching all the numbers we came up with a custom grind of 226/238 duration and a bump in lift to 0.585/0.605 inch. We knocked the LSA down to 114. This combination should net us more power and retain almost all of our streetability.

After applying a generous amount of assembly lube, we carefully slid the COMP bumpstick into its new home.

With the cam in place, we secured it using the original GM retention plate.

We then installed the LS7 upper sprocket and chain from the COMP kit (PN 3167KT, $180). The LS7 version was used since it utilized the four-pulse design and was compatible with the three-bolt camshaft. Keep in mind that it’s not necessary to swap over the crank sprocket, but since it came in the kit we decided to use it.

Since we were there, we decided to replace the stock pump with a high-volume pump from Melling (PN 10296).

With that done we buttoned up the front of the LS3. The only RTV required in this whole deal was a dab at the two lower corners of the timing cover where it met the oil pan.

Moving back to the heads we used a spring compressor to remove the locks in preparation for installing the new COMP Ultra dual valvesprings (PN 26925-16, $186.95) and hardware. These 400 springs matched up nicely with the higher lift characteristics of our new bumpstick.

With all 16 springs swapped out we then installed the new COMP Hi-Tech hardened chromoly pushrods (PN 7955-16, $135). With a diameter of 5/16 inch and a length of 7.400 inches, they were a simple drop-in deal. Once in place we installed the new Yella Terra roller rocker arms (PN YT-6668, $498). These pieces are lightweight and super strong with cross-shafts for better stability at high rpm. Best of all, they fit under the factory valve covers.

After reinstalling the valve covers and coil packs it was time to finish up. We secured the idler and bolted the water pump to the front of the LS3.

We finished the project by reinstalling the cooling system and putting the air induction parts back in place. The only thing left to do was strap it to the dyno for tuning.

Before we started this whole exercise we strapped down the Camaro and made a few dyno pulls. Our best pull, with the stock valvetrain, was 556 hp and 519 lb-ft of torque. With the new cam, springs, and rockers we were rewarded with a best pull of 678 hp at 6,400 rpm and 607 pounds of twist at 4,300 rpm on 8 pounds of boost. CHP