Another challenge! There's what appears to be an oil gallery at the driver's rear of the early 283 I'm rebuilding and when the machine shop cleaned my block they pulled the old plug out. Thinking it was threaded, I got a 1/2 inch plug...but apparently the hole is not threaded.

Here we go again, just like the crank bolt issue, no threads and I need to plug this hole or I'm going to have a major puddle (and no oil pressure) on start-up!

I was test fitting a cylinder head when I saw it, and the machine shop doesn't have a small plug I could drive in with a punch. Am I going to have to cut threads on this? I have a pic of the spot but no easy way to hang a pic here without using a photo-sharing site.