I saw a site where a fellow had vented his crankcase off the timing pin hole with a 3/8 hose barb in place of the blanking plug. I looked for the site again but can not find it right now. My question is: What is the thread size in said hole and is a hose barb readily available. I ask because I measure it a 12 TPI and about a 3/8 hole. In checking my taps , I find 12TPI in 9/16 but not 3/8. Any insight would be of interest. Working on a 1970 T120R.