Skip to product information
1 of 3

Beehive Spring Kit, Rocker Shim Conv. System, 0.625” Lift, HD®, M8 2017-2023

Beehive Spring Kit, Rocker Shim Conv. System, 0.625” Lift, HD®, M8 2017-2023


Regular price $519.32 USD
Regular price $519.32 USD Sale price $519.32 USD
Sale Sold out
Retainer Material

California Prop 65

  • Innovative design adds a Ø9.5mm hardened steel shim between the valve tip and rocker arm
  • The Ø9.5mm shim increases allowable rocker wipe area for maximum valve lift
  • Up to 0.625” valve lift compatibility
  • Offered with either Titanium or H.T. Steel retainers
  • Includes Heavy Duty 9° H.T. Steel Keepers, Ø9.5mm Steel Shim, Red Viton® Seals and a HT Steel Basewasher

The KPMI® Rocker Shim Conversion Spring Kit for the Milwaukee-8 utilizes the proven KPMI 0.625" beehive spring and a lightweight retainer that houses a standard Ø9.5mm hardened steel shim. The rocker arm rides directly on the shim surface and the 9.5mm diameter significantly increases the allowable rocker wipe area. This increase in wipe area provides the ability to utilize larger lift cams, that previously were unable to run on a 6mm valve stem. Additionally, the rocker shim thickness can be varied to adjust effective stem protrusion.

When larger camshafts are used, and valvetrain acceleration values increase, KPMI® strongly recommends running titanium valves for maximum performance

Modification Necessary:
To maximize shim contact in the retainer, KPMI recommends “tipping” (shortening the valve tip). See KPMI® installation instructions for more info.
Stem Protrusion:
There is anticipated to be a rough 0.100” increase in effective stem protrusion with the use of the shim.

Installation Instructions Click Here for Kit, 20-23900
Click Here for Kit, 20-23950
Type Intake/ Exhaust
Retainer Material Titanium or H.T. Steel
Valve Lift 0.625"
Installed Height 1.500"
Seat Pressure 85#
Open Pressure 280#
@ Lift 0.625"
Unique Identifier No. FR327789_01GAUS
View full details