The gas block is a JPGS-8.
From their install sheet;Run a 6-32 H1 or H2 bottoming tap into the gas adjustment hole from the side to score the gas tube. A normal tap may be used, but the tip may have to be ground off. The purpose here is to cut threads into the bottom of the gas tube to allow the adjustment screw to position tightly against the gas tube. This tapping can be performed even though the detent mechanism is in place.
This is one of the things that's got me messed up and looking for a more simple gas block
