Shaft-mounted rocker arms are usually reserved for the high-stress environment of an all-out racing engine-whether it's for drag racing or some other competitive motorsport. Most of us late-model Mustang 5.0 enthusiasts have been limited to either a bolt-on pedestal-mount rocker arm or a stud-mount arm for a more high-performance application.
Now the scene has changed with the introduction of these Jesel shaft-mounted rocker arms, which are a considerable upgrade from stud-mount rockers. By eliminating studs, guide plates, poly locks, and stud girdles, the entire valvetrain setup is greatly simplified, and the durability and precision of the company's Winston Cup shaft rockers is also significant. There's also the benefit of better-maintained valve lash, reduced valveguide wear, and fewer required valve jobs on the cylinder heads at rebuild time.
These shaft-mount rockers will fit several types of heads, including stock 5.0, any FRPP aluminum GT-40, cast-iron GT-40P (the ones in our '93 coupe subject car), Brodix ST 5.0 Track 1, Edelbrock 7716 Victor Jr., World Products Windsor Jr./Sr, Roush 180/200, and most other aftermarket Ford heads that use typical pedestal- or stud-mount rocker arms. Available ratios include 1.5, 1.6, and 1.7:1. Let's look at the installation procedure.