I removed the lifter gallery cover and checked the pipe that feeds oil to the rocker shaft. It appeared to be good. I then pressurized the water jacket at the upper radiator hose, plugging the lower hose. I got air through the oil line feeding the rocker shaft. Do you know if this is accessable once it goes into the water jacket, maybe at the oil distributor valve? I also got air at a connection on the opposite side of the block that connects to the oil pump cover. This suggests that maybe something is not connected or broken in the water jacket??
