One of the differences on this block is lack of china-wall oil ports which i was using for my idiot light sensor and to feed valvespring oilers. So my idea is to use the NPT ports on the side of the block, I'm always open to other suggestions... Apparently someone didn't want anyone EVER to remove these internal hex NPT plugs because they cranked them in all the way to China! I assume it's because they didn't want to use any NPT sealer so, tight is right? IDFK So, I had to get creative because tapping-in the metric oversize allen wrench still stripped out the hex, Whiskey Tango Foxtrot.