What is the benefit of a 1.5:1 rocker arm ratio?

A 1.5:1 rocker arm ratio means the valve opens 1.5 times the amount the rocker arm stud moves. This generally results in increased valve lift, which can help your engine breathe better by allowing more air and fuel in and exhaust out, potentially improving performance.

What materials are these rocker arms made from?

These S&S Cycle rocker arms are machined from 8620 steel forgings. They are then heat-treated to ensure they are strong and durable for use in performance engine applications.

What other S&S Cycle components are recommended for this rocker arm set?

For optimal performance and top-end oiling, S&S Cycle recommends using these rocker arms in conjunction with their billet tappet guides and Quickee pushrods. They are also compatible with both S&S billet and stock rocker boxes.

Specifications

Brand: S&S Cycle
Part #: 900-4320A
UPC: 900-4320A

S&S Cycle 66-84 BT 1.5 To 1 Ratio Rocker Arm Set

Name: S&S Cycle 66-84 BT 1.5 To 1 Ratio Rocker Arm Set
Brand: S&S Cycle
SKU: s-s-cycle-s-s-cycle-66-84-bt-1-5-to-1-ratio-rocker-arm-set-t14-664538
Price: 656.79 USD
Availability: BackOrder

$656.79

On Backorder — Expected to ship by May 7, 2026

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

1977-1984 Harley-Davidson Rocker Arms: S&S Cycle 1.5:1 ratio roller rocker arm set for improved engine performance.

Key Features

Fits 1977-1984 Harley-Davidson FLHS Electra Glide Sport, FXS Low Rider, FXSB Low Rider - Belt, and FXWG Wide Glide.
Features a nominal 1.5:1 rocker ratio for increased valve lift.
Machined from 8620 steel forgings and heat-treated for maximum strength.
Includes exclusive .750 in. long S&S rocker arm bushings with 50% more load-bearing surface than stock.
Compatible with S&S billet and stock rocker boxes.
When used with S&S billet tappet guides and S&S Quickee pushrods, allows for top-end oiling.

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About this part

Product Details

S&S Cycle is well-known for making performance engine components for Harley-Davidson motorcycles. If you're working on the top end of your Shovelhead engine, this 1.5:1 ratio roller rocker arm set is a solid option for improving your engine's breathing and performance. These arms are designed to work with S&S billet and stock rocker boxes, and when paired with S&S billet tappet guides and Quickee pushrods, they enable top-end oiling for better lubrication.

These rocker arms are machined from 8620 steel forgings and then heat-treated to ensure they are strong enough for demanding use. They feature an exclusive .750 inch long S&S rocker arm bushing, which offers 50% more load-bearing surface compared to the stock .500 inch bushings. This increased surface area helps distribute the load more effectively, contributing to the longevity and reliability of the valvetrain.

This set includes rocker arms with a nominal 1.5:1 ratio, meaning the valve opens 1.5 times the amount the rocker arm stud moves. This ratio change can help increase valve lift, allowing more air and fuel into the cylinder and more exhaust out, which can lead to improved engine performance. This kit is designed as a direct fit for a range of Harley-Davidson Big Twin models from the late 70s through the mid-80s.