Thanks. Perhaps I'll look for a piece of flat lead and make a few. I may also use some Masters Pro-Dope with Teflon Pipe Thread Sealant (liguid by Dupont) that is good for oil, gas, water, natural gas, etc. I intend to use it as well on the 4 echaust manifold studs that aslo extend into the water jacket (and no place there ofr lead washers). Good for 10,000 psi and 400+F.
And perhaps whilst i'm at the gathering of the Green i can slip by the factory and get the JD part!