Metafoam base gasket for knuckle/UL/ULH
This is a Metaform rocker box nut gasket made by Reverb for 1936-48 knuckle/side valve big twins.
As those who have built knuckles know, this washer is quite thick for VTWIN and Eastern products currently on the market, and if you assemble it as is, the nut will float quite far from the rocker box, ...