Twizzle donated a few scans of the installation instructions
of a Harman 120,
they are kind of hard to read so I added a "translation" Here
is part 1:
120 Inch Street Assembly Instructions
cylinders honed for pistons (usually .008 clearance)
flywheels to clear rods if Carello rods are to be used.
Stock flywheels must also be checked for rod clearance
crank without rods so it can be balanced, usually
50% to 60% overbalance
piston weights & make spacers to fit between piston
inside bosses and rod ends. Also check rods fit between each
other at bottom of stroke. Get crank balanced now.
timken races into cases and pinion race in cases.
Line lap cases now and fit rod bearings to crank pin if crank
is back from balancing.
balanced crank now. Locktite and torque all crank
breather window in cases to S&S specs. Debur breather
oil pump surface for burrs and block sand it ruff.
oil pump on cases being sure to have either
matching early or late drive gears. When tightened down on
cases, pump must turn without great effort. Threads in
cases are 1/4 x 20
rod side play-need about .012 to .015
threads on pinion shaft to be sure the nut goes on
flywheels into sprocket case only & check to see
that when torqued up tight the flywheels turn free & easily
or you must disassemble and install a thicker spacer
install pinion case & silicone cases together. Be sure
rods are centered in cases. Oil rod bearings now.