09-19-2021, 10:07 AM
It appears that it is a 1/2-14 npt pipe plug. Since it is just a plug, there is no way to use a washer. If I tried, I think I could continue tightening it until he goes completely in the oil pan. Thant would make my day. It has a recess on the end of it it to accept 3/8 inch ratchet and extension to tighten with . I thought it was something special ! Tomorrow I will go get a standard 1/2-14 oil drain plug that has a with a washer and a shoulder for the washer. Maybe when this engine was overhauled in 2013 they lost the original plug, and decided and electrical type cap plug would do the job? If you GOOGLE 1/2 npt cap plug, that's what I have.
Guy & Sue
1984 Classic 40' #59