Installation Instructions for 20500, 20505, 20510 and 20515 Rocker Arm Stud Girdle

1. Install the adjusting nuts with the stop clip at each end of the head (end exhaust valves) this will prevent the stud girdle bars from being positioned too close to the rocker arms. Install six adjusting nuts without the stop clips on the remaining rockers and adjust them according to the cam manufacturer’s recommendations. 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 setscrew is not needed with the stud girdle; the aluminum bars will hold the adjustment nuts in place.The remaining head can now be serviced as the first.

2. Place the aluminum stud girdle bars on the adjusting nuts and slide them down until they bottom at the stop clips. Make sure they “DO NOT” come in contact with the top side of the rocker arms, or severe damage will occur. Tighten the bolts that will clamp the bars around the adjusting nuts to a maximum of 25 ft/lbs.

3. After the stud girdle bars have been properly installed, re-check your valve lash adjustment, 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 adjusting 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 all the components adequate time to seat.

Kit Includes:

2 - Stud Girdle Bar Assemblies

12 - Adjusting Nuts 4 - Adjusting Nuts with Clip

Replacement Parts:

555-20501 3/8” Adjusting Nut

555-20502 3/8” Adjusting Nut with Clip

555-20506 7/16” Adjusting Nut

555-20507 7/16” Adjusting Nut with Clip