S&S Cycle Rocker Boxes for 1966-84 Big Twin - Manual (Page 6)

NOTE: When using S&S tappet blocks (33-5451) in conjunction with an 1984-1999 cam you must recalculate the max valve lift for the shovelhead rocker
ratio using the following formula.
14. Install hollow fl anged bolt onto the two shortest studs in your heads. See Picture 13, below left. Torque fl ange bolts to 18 ft-lbs.
NOTE: If you are using stock Harley-Davidson® heads manufactured prior to 1979 you will need to remove 1 long stud per head (See Figure 1, below
right) and replace it with Harley-Davidson® PN 17508-66. A propane torch is recommended for heating the head prior to attempting stud removal.
All reference to Harley-Davidson® part numbers is for identifi cation purposes only. We in no way are implying that any of S&S® Cycle’s products are
original equipment parts or that they are equivalent to the corresponding Harley-Davidson® part number shown.
6
Picture 13
Remove long studs from these locations
Front Rear
Figure 1
1984-1999 cam valve lift
1.625 (rocker ratio)
= Cam lobe lift
Cam lobe lift X 1.5 (S&S rocker ratio for shovelhead) = Corrected lift for shovelhead engines