I stripped the first few threads putting it back in after a flush (hot hot day ,sun fried,tired,and didn't think I had taken the bolt all the way out.But I did, and went to thread it and it seemed to thread in (until it didn't.ofc.) I imagine the iron block threads are fine. Question is , what's the dang actual thread, so I can get a die to chase them? Ai is telling me it's 1/4inchNPT-18. But it also told me it was standard 1/4"NPT. I'm confused AF, but can get a single die delivered and have access to a "standard "1/4"NPT thread (apparently that 1/4"npt-20) on Thursday. I'm not buggin, I'm doing timing,wp,and oil pump and that plug can be one of the last steps [gonna be hot so I planned to do it over the course of a few days](before coolant fill) and I'll inform you all if I get no responses by Tomorrow, when I don't feel every second of my age punching me in my joints I'll take the bolt to a local hardware store and see if I can find the actual thread then.