Aftermarket roller rocker arms have been around since the '60s and while the basic design is still here, they have definitely evolved. They have gotten stronger, lighter, and basically better. Roller rockers are a pretty easy way to reduce friction in the valvetrain and, in turn, free up some horsepower. They can also be ordered with different ratios that can increase your cam's lift without pulling the cam.
If you have been reading Super Chevy lately, then you know we unearthed a '70 Z28 Camaro that still has the LT-1 350 in it. The motor was given a dose of aftermarket parts some time ago in the form of a solid-lifter Z-30 cam from Isky, a set of 1.6 ratio rocker arms, and heavy-duty valve springs. At some point the factory 1.5 ratio rockers were swapped out with a 1.6 ratio set. This raises our cam's lift from 0.480 to 0.512. While these components are in working order, we found an issue with the rockers when we pulled one off for inspection. The rocker arms are showing wear, in that the roller at the tip is cutting into the body of the rocker.
As close as we could tell, these rockers were manufactured in '74 so they have done their job, but this wear issue had us wanting to change them out.
We contacted the valvetrain gurus at Comp Cams to see what's new in the way of rockers and related parts. We were in luck, as Comp just recently redesigned the company's Gold ARC rockers and came out with a new two-piece guide plate.
The next-gen Ultra-Gold ARC aluminum rocker arms (which come with poly locks) are manufactured here in the USA. According to Comp, these rockers increase engine power, enhance valvetrain stability and improve oiling. The new extrusion-based design was developed through Finite Element Analysis (FEA) and results in a stronger, stiffer body without compromising mass. The arced channel and contoured top come together to create an unbeatable strength-to-weight ratio.
We also got a fresh-off-the-press two-piece guide plate set. The all-new design really helps speed up adjustment, especially on heads with valve centerline modifications. They are created from die-stamped and heat-treated steel for improved durability. They also feature an interlocking design that makes adjusting them very simple. Right now they are only offered for 7/16 base threaded studs and 5/16 diameter pushrods.
Speaking of pushrods, Comp's one-piece Magnum pushrods are constructed from one-piece 0.080-inch wall chrome-moly steel tubing that have been precision formed with reinforced ends. Then they're heat-treated for extended durability and guide plate compatibility. They are coated in a sweet black-oxide finish and even have the part number and length laser-etched on the side.
All this would be nothing without a stud to mount them to so we decided to upgrade from 3/8 to 7/16 studs. The Hi-Tech race stud features a thin jam nut for rocker clearance, rolled threads for maximum contact, and a ground-flat top. The diameter of the jam nut is larger in order to spread the load over a larger area. The studs also have generous radii and a black-oxide finish.
To help us install stuff while we snapped the pictures, we enlisted the help of Ali Mahmoudi. We want to thank him for spending a few hours at our shop getting dirty underhood while we stayed clean behind the camera.
Parts and Prices
|Gold ARC Rockers w/locks||19005-16||$309.38|
|Adjustable Guide Plates||4835-16||$53.51|
|Hi-Tech Race Stud 7/16-in.||4506-16||$56.61|