Part No. | Models | Year | Description |
R0009-41A [set] | WR | 1941-1947 | Aluminium head set. Wide gasket area. Valve pockets closer to bore and sized for the WR unique valve head measurements [1.81" In. & 1.56" Exh.] |
R0009-48A [set] | WR | 1948-1952 | Aluminium head set. Wide gasket area. Valve pockets closer to bore and sized for the WR unique valve head measurements [1.81" In. & 1.56" Exh.]. Heads have a piston relief for use of special pistons that extend into the head at TDC*. |
*TDC: Top dead Center: "highest" point of piston travel.
Extra special thanks to Beachdog for providing this information gathered during more than 30 years dealing with WLDR/WR bikes.