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Installation Instructions for 20518 Rocker Arm Stud Girdle

1. Install the adjusting nuts with the longer set of adjusting nuts on the intake valve rocker studs and the shorter set of adjusting nuts on the exhaust valve rocker studs. Adjust the rocker arm nuts to the cam manufacturer’s recommended setting(s). Once the proper adjustment has been set, you only need to tighten the set screw against the top of the stud. The need to “JAM” tighten the adjusting nut into the set screw is not needed with a stud girdle; the aluminum bars will hold the adjusting nuts in place. The remaining cylinder head can now be serviced, same as the first.

2. The bottom of the aluminum stud girdle bars have machined “pockets”. Place the aluminum stud girdle bars with the machined “pockets” towards the rocker arms on the adjusting nuts and slide them down being careful to not set them too low. The top of the girdle should be level with the top of the shank of the lowest rocker arm adjusting nut leaving at least the entire height of the hex portion of the adjuster exposed. Make sure the girdle“DOES NOT” contact the top side of the rocker arms during the range of movement, or severe damage will occur. Tighten the bolts that clamp the bars around the adjusting nuts to a maximum of 25 lb/ft.

3. After the stud girdle bars have been properly installed, re-check your valve lash adjustment as it may have changed with the installation of the stud girdle bars. If re-adjustment is required, loosen the bolts on the stud girdle bars closest to the rocker arm needing the adjustment sequence. Then re-tighten the bolts and re-check the adjustment. You may need to add or subtract from the specs of your adjusting sequence to compensate due to the adjusting nuts being pulled into alignment with accurate CNC machined stud girdle bars.

4. We recommend that the rocker arm adjustments be checked three to five times before constant running of the engine is sustained. This will allow the components adequate time to seat.

Kit Includes:

2- Stud Girdle Bar Assemblies

8- Intake Valve Rocker Arm Adjusting Nuts

8- Exhaust Valve Rocker Arm Adjusting Nuts

Replacement Parts:

555-20506 7/16” Exhaust Valve Rocker Arm Adjusting Nut (Short)

555-20508 7/16” Intake Valve Rocker Arm Adjusting Nut (Long)

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Posted on
May 10, 2018
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