That's great info!
However, if a hex plug gets wedged in there good you will have a terrible nightmare of a time removing it, because when you put a tool into an internal hex plug and turn it, the plug EXPANDS. The teflon tape will help prevent this from happening, but it's still a risk. The lip of the D50 sticks out more than enough to protect an external square head.
1992 F250 XLT 4x4 Super Cab 7.3 IDI E40D 3.55 ATS 088 4"R.C 360k
1982 MBZ 300SD W126 California model w/Sunroof, no EGR