Thank you Hotrod. I'll get some Permatex Super 300. Would that work on the freeze plugs too?
My engine is a 37 and the diagram from the previous thread looks just like the one in my shop manual. I didn't have any trouble fishing the copper line through the block.
The front freeze plug had a hole in it and was leaking a little coolant. I pulled both of them out and the rear one had so much gunk behind it that it looked solid. Nothing came out of the lower drain plug when I removed it.
I used a pressure washer in the holes and a length of speedometer cable on a drill and finally got the lower drain working. I don't think the coolant had ever been drained from the engine before.
With all the thick greasy sludge in the lubrication system and the crud in the coolant system its a wonder that the engine was running at all. I hope it runs again when I get it all put back together.