When the OE heads were pulled, we got another pleasant surprise. The cylinder walls were smooth, clean, and unscarred, and the pistons had very little carbon build up on them.
The deck surface of the block was scraped clean, wiped down and was ready for the new Edelbrock cylinder heads.
While the stock 5.3L cylinder heads can do a decent job, to really wake up the 5.3, we went with Edelbrock Performer RPM Xtreme LS-series heads. The RPM Xtreme cylinder heads (PN 61949) are cast aluminum and CNC-machined in all the critical areas-combustion chambers, intake and exhaust runners, and intake and exhaust bowls. At $2,073, this combination makes them more affordable than a set of fully re-worked stock heads. These cylinder heads feature 65cc combustion chambers, 214cc intake runners and 80cc exhaust runners. The intake valve size is 2.02-inch and the exhaust valve is 1.57. They also come with a 5/8-inch deck surface should you decide to machine them for additional compression. Compare these numbers to the numbers of the stock heads. Bigger valves plus bigger runners equals better breathing.
For a cost of $3,073.85, we had a stout cruising engine with 357 hp and 380 lb-ft of torque that gets great mileage. At this price, what's not to love? But this wouldn't be Super Chevy magazine if we left well enough alone, so we're going to perform a few more installs and bump up the power.
While Steve cleaned the deck surface, Ernie installed the Comp Cams Xtreme RPM roller cam (PN 54-416-11). We included a shot of the cam card for your viewing pleasure. The cam's effective range is from 1,660 rpm to 6,600 rpm; intake duration at .050 is 220 degrees, exhaust duration at .050 measures 224 degrees with a 112-degree lobe separation. Using the factory rocker arm ratio, the intake valve lift is 0.530-inch and the exhaust is 0.534-inch.
The factory torque-to-yield bolts are not reusable; Edelbrock suggests using ARP head bolt kit (PN 134-3609).
One thing to note before putting on the cylinder heads: Use the correct head gasket. In the Fel-Pro line, there are two different types of gaskets for these engines. One is for the 5.3L and one is for the 5.7L. The 5.3L head gaskets will not work with these newer Edelbrock heads; the 5.7L LS1 head gaskets are the correct ones to use due to the increased combustion chamber size.
Salvaged Engine $800HP Tuners $649
Edelbrock Cylinder Heads $2,073ARP bolts $149
Summit 80mm Throttle Body. $269.95Painless Wiring system $589.95
Comp Cam $399.95Hooker Headers $704.95
Total $5,635.08prices taken from the Summit Website.