Stock 1:1 rocker ratio. Will fit stock 40-47 Knucklehead and is stock replacement for S&S KN-series engines. Note: S&S rocker arms & shafts must be used as a kit. S&S rocker arms are not compatible with stock shafts. S&S shafts are not compatible with stock rocker arms. Note: See 531976 for replacement rocker set only for this 531975 kit.Note: Special Order Product only. To order please contact your MCS sales representative.

