Oil Pan Dipstick?

The truck block is no different from a passenger block. The plug should just punch out. Is your punch too big in diameter?

I don't think so. I was able to leave an indent in the plug with my punch. I went ahead and filled up the hole with PB Blast for the night. Fingers crossed that will help break down some of the gunk in the hole. This block has sat out side for over 10 years so everything has been pretty tough to get off. Like I had to take the oil pump off in two pieces as it just wouldn't break its hold onto the block.