It’s no secret that if you’re looking to make big power, GM’s LS engines are an excellent place to start. While these engines are incredibly powerful and durable, they do have a few weak points–many of them in the valvetrain. The search for power means adding bigger cylinder heads, longer duration camshafts with more lift that also demand stronger valve springs. All these improvements also increase the load on the stock LS rocker arm.

As a stock component, the LS rocker arm is a well-engineered piece. Despite its compact size, this investment cast rocker is incredibly strong and uses a roller bearing fulcrum which is a vast improvement over the high-friction ball and stud arrangement of its small-block Chevy predecessor. But with these increased spring loads, the stresses are also greatly increased on the stock fulcrum.

The good news is that several companies make an upgrade kit. Summit Racing has not only produced a kit that increases the strength of the trunnion and bearings, but has created a great little installation tool that makes the conversion very easy. Even stopping to shoot photos along the way, we had a complete set of 16 roller rockers converted in less than an hour.

Here’s how we did it:

assortment of old gm ls rocker arms in a pile
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We unbolted a set of very well used LS rocker arms and upgraded them to a much stronger and more durable Summit Racing trunnion kit for much less than the cost of a set of aftermarket rocker arms.

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Parts List

Summit Racing LS Rocker Arm Bearing Kit (SME-143002)
Summit Racing Rocker Trunnion Install Tool (SME-906011)
Summit Racing LS Rocker Bearings (2) (SME-143002-2B)

Keywords
LS tech, LS trunnion kit, Summit Racing
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Author: Jeff Smith

Jeff Smith has had a passion for cars since he began working at his grandfather's gas station at the age 10. After graduating from Iowa State University with a journalism degree in 1978, he combined his two passions: cars and writing. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. In 1987, he assumed the role of editor for Hot Rod magazine before returning to his first love of writing technical stories. Since 2003, Jeff has held various positions at Car Craft (including editor), has written books on small block Chevy performance, and even cultivated an impressive collection of 1965 and 1966 Chevelles. Now he serves as a regular contributor to OnAllCylinders.