S&S Cycle 590 Lift Valve Spring Kits 90-2060 and 90-2063 for 1948–1984 Big Twin Engines User Manual

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High lift camshafts and related components require careful assembly of cylinder heads and rocker assemblies to assure that adequate
clearances exist. Read these instructions completely before beginning installation. Failure to follow recommended procedures can
cause extensive engine damage not covered under warranty.

S&S® valve spring and collar kits #90-2060, and, #90-2063 permit valve lifts up to .590" in 1948–1984 big twin engines. Valve guides will likely
require modification to permit maximum lift. S&S .590 lift springs can be identified by a yellow stripe as well as the triple spring configuration.

Pressures for triple spring assembly are as follows: Closed valve—158 lbf; .540" lift - 339 lbf; .590" lift - 353 lbf. Kit #90-2060 is designed for use
with stock 1948–early ‘81 cylinder heads, valve guides and associated parts. Kit #90-2063 is designed for 1981–’84 models and S&S Super Stock®
cylinder heads for 1966–’84 big twin engines and associated parts. Kits accept stock valve keepers.

NOTE: S&S Spring Kits #90-2060 & 2063 can be used as assemblies to replace stock valve springs in stock cylinder heads, but individual parts from S&S

and stock spring kits cannot be mixed.

Mixing of springs or collars from other type spring kits may cause engine damage.

Spring Installation Procedure

1. Remove heads from engine and disassemble. If cylinder heads/valves are to be reconditioned, proceed at this time according to standard

procedure. Refer to Harley-Davidson® service manual as necessary.

NOTES:

• 1948-early ‘81 big twin cylinder heads have unmachined valve spring pocket and require S&S bottom collar #90-2059 designed to rest on valve

guide flange rather than cylinder head. See Pictures 1 & 2, above. Because stock valve guides for these models are no longer manufactured,
S&S lower collar is designed to fit aftermarket and Harley-Davidson® repair guides only. Flange of stock guide is too large for S&S lower collar.

• Late ‘81–’84 shovelhead has machined valve spring pocket and require S&S bottom collar #90-2062 designed to rest directly on cylinder head.

See Pictures 1 & 2, above.

2. Using following procedure, determine installed spring height and clearance between top collar/valve keepers and valve guide for each valve

and spring assembly. Once clearances have been measured, keep parts separate and use only in location where measurement was obtained.
For example, valve and spring assembly used to measure clearances on intake side of front head must be installed in that location.

All reference to Harley-Davidson® part numbers is for identification 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..

CAUTION

Picture 1: 1948–Early ‘81 (left) and Late 1981–’84 (right) valve

spring pockets.

Picture 2: This exploded view shows lower spring collar

and shim stack-up for 1948-Early ‘81 (top) and
Late 1981-’84 (bottom). Note early engines did
not originally come with valve seals. If using
aftermarket valve seals, follow manufacturers
directions.