S&S Cycle Super Stock Cylinder Heads for 1966–1984 Shovelhead Models - Manual (Page 4)

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• Shape and volume of combustion chambers is same as stock. Valves and valve seats are compatible with present day fuels.
• 5⁄16-18 cap screws are provided for rocker housing installation.
NOTE: Rocker arm housings must be installed with 5⁄16 -18 cap screws. Harley-Davidson® rocker housing studs are different thread.
NOTE: Some rocker housings require 5⁄16 -18 x 11⁄2" bolts in rear, cam side position of both rocker housings, others utilize 5⁄16 -18 x 21⁄2" bolts in all locations.
See Figure 3, below. S&S kit includes both lengths. Extra 11⁄2" or 21⁄2" bolts will not be used. All rocker housings utilize 11⁄2" bolt in center location between
pushrods.
Attempting to install Harley-Davidson® or similar rocker housing studs in S&S® Super Stock® Cylinder Heads for shovelhead models will
result in damage not covered under warranty.
• Machining for dual spark plugs and external oil drains is optional.
NOTE: When external oil drain option is specified, S&S blocks stock-style internal oil returns in each head prior to assembly and machines external passages
to accommodate 1⁄8-27 NPT fittings for external return. Fittings are provided but must be installed by customer who must also provide and install the lines
themselves. Return line from each cylinder head should be joined with tee (not provided) approximately at level of crankcase. Third line must then be
attached to tee and routed to primary oil scavenge passage located between oil pump and center of crankcase. See Picture 1. If engine is ever converted
to stock, internal oil return, heads must be disassembled and internal oil passage plugs removed. External passages must also be blocked with 1⁄8-27 NPT
pipe plug.
Figure 3
CAUTION
Picture 1
Primary scavenger fitting location