PROFORM: Comparing Rocker Arms For Small Block Chevys

Caecey Killian July 28, 2025 5 min read 0

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When it comes to valvetrain upgrades for your small-block Chevy, few components are as critical, or as misunderstood, as the rocker arms. Whether you’re building a mild street cruiser or a full-blown race machine, the right rocker arm setup can make a significant difference in engine efficiency, power delivery, and component longevity. That’s why PROFORM offers a full lineup of rocker arms for small-block Chevys, from cost-effective stamped steel to race-bred aluminum full roller designs. And because not every engine build demands the same hardware, they also offer combinations of ratios and stud sizes to suit your specific goals.

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Understanding Rocker Arm Designs

At a glance, rocker arms may seem like a simple part of the puzzle, but there’s a lot going on under the valve cover. The most basic style PROFORM offers is the long-slot stamped steel rocker arm, like their 1.5 ratio (P/N 66905) and 1.6 ratio version (P/N 69461). These units are essentially OEM-style rockers with reinforced slots that help prevent stud interference when using higher lift cams.

Stamped steel arms are simple, affordable, and reliable for lower-RPM street builds or budget refreshes. They don’t offer the friction reduction of rollers, but they’ve proven themselves in countless builds where durability and cost are key factors. PROFORM even offers a full kit with stamped long-slot rockers and pushrods (P/N 66923C) for full valvetrain replacement on older SBC builds.

For builds looking to split the difference, PROFORM offers stamped steel rocker arms with roller tips, often called “roller tip” rockers. These hybrid units reduce wear at the valve tip while retaining a ball-style pivot, like in P/N 66922 and P/N 66906B. They’re ideal for weekend warriors or street/strip combos that see spirited driving without needing the full performance benefits of a race-grade valvetrain.

Then there’s the top of the line: full roller rocker arms, like PROFORM’s Super Street Series aluminum rockers. These feature full needle-bearing fulcrums and roller tips for drastically reduced friction, better valve motion, and higher RPM potential. Their lineup includes a wide range of ratios and stud sizes, like the 1.6 ratio, 7/16” stud version (P/N 66910), or the common 1.5 ratio, 3/8” stud model (P/N 66907).

These are machined for precise ratio consistency and come anodized with the PROFORM “P” logo laser-etched into each arm. For engines with aggressive cams or higher spring pressures, this is where you want to be.

Choosing Between 1.5 and 1.6 Ratio Rockers

The ratio of a rocker arm refers to how far the valve is opened relative to the amount of pushrod movement. A standard small-block Chevy came with 1.5 ratio rockers from the factory. Switching to a 1.6 ratio rocker increases valve lift without changing the camshaft, which can boost power but also increases spring pressure and valve motion speeds.

For example, if your cam is ground for .480” lift with a 1.5 rocker, swapping to a 1.6 will yield .512” lift. That may benefit flow, but it could also risk coil bind or piston-to-valve contact if your clearances are tight. That’s why PROFORM sells rockers in both 1.5 ratio and 1.6 ratio, or even a combo pack like P/N 66920C with both ratios included to fine-tune intake and exhaust performance separately.

Stud Size: 3/8” vs. 7/16”

Another important factor is rocker arm stud diameter. Most production small-block Chevy heads use 3/8” rocker studs, but higher horsepower builds benefit from the added strength of 7/16” studs. They offer more resistance to flex and failure under high RPM, high spring pressure loads.

PROFORM has options for both setups. Their P/N 66909 and P/N 66910 are 7/16” options made for upgraded heads or racing builds, while P/N 66907 and P/N 66908 fit the more common 3/8” studs used in most factory heads.

It’s critical to match your rocker arms to your cylinder head and valvetrain combination. A mismatch in stud size or clearance can result in poor geometry, broken parts, or engine damage.

Find Them at Trusted Retailers

Whether you’re looking to pick up a fresh set of stamped steel rockers or dial in your next high-revving combo with a set of aluminum rollers, PROFORM parts are widely available through top-tier retailers like Jegs, Summit Racing, and Speedway Motors. These vendors regularly stock both rocker types in all the common ratios and stud sizes, giving builders the flexibility to order what they need quickly and confidently.

Final Thoughts

No matter where your small-block Chevy project lands on the performance spectrum, PROFORM has a rocker arm solution that fits. Their full lineup, spanning stamped steel, roller tip, and full roller designs, offers the flexibility to dial in the right valvetrain setup for your heads, cam, springs, and RPM range. Whether you’re working with a street 350 or a high-strung 406, these parts deliver durability, performance, and the value that makes PROFORM a staple in builds across the country. Stay tuned as Car Junkie Mag breaks down more PROFORM products!

AboutCaecey Killian

Caecey Killian covers builds, installs, and product features for Car Junkie Magazine. He has spent years on the floor of the garage chasing horsepower across SBC, LS, and modern muscle platforms, and that shop time runs through every article he writes. His current CJM project is Project Street Reaper, a 1976 Camaro built around a fresh SBC 350. He is also known for Project Mighty Mouse, a 1977 Chevy Nova running a 1962 small-journal 327 SBC, with build coverage published across multiple online automotive magazines. His media background spans long-form build documentation, install coverage, and product features across the magazine and the Car Junkie Magazine YouTube channel. He writes the way he wrenches: specific, honest about the mistakes, and grounded in real garage work.