Brian I made up block off plates for every coolant area of these idi engines. Your welcome to use them if you can wait for shipping. I even made head plates that look just like a head gasket.. But they are 1/2 inch thick aluminum with rubber gaskets on them. You bolt them to the block and can see down into the cylinders for leaks.
Gary, I just may do that!
I can make the oil cooler ones easy enough, but if I have to dig deeper, I will take you up on your offer.
thanks bud!