I put an 848 head on my 261 engine. Being the trained master machinist that I am, I place a head gasket on the head, took my 3/8 hand drill and said that must be the right angle and drilled the holes. It's been running that way for 3 years now with no problems. But now that I have said that I'm sure that Mr Murphy will come calling. I know that you have to be careful for the water jacket when you do it. I sure that wasn't much help but it worked for me.
