Originally Posted by
N1EDM
Thanks for that, George. I didn't know that the automobile level parts were Grade 8. That was my concern. Handy information to know.
Bob
Look, or ask for automotive washers that are used under bolts or nuts holding heads or manifolds to the block. They are precise, flat, hard, and thicker than normal washers. Equal in my opinion to mfr. supplied prop washers. You may have to go to a parts supplier that has rebuild hardware, rather than pep boys or advance auto.