for the 4.0 OHV team:
I ran a 16.7 @ 80mph a few years ago with my 92 auto sport 4.0 OHV / 3.08 open diff / a few mods (exhaust, KKM, etc).
I now have 3.73 rearend with a powertrax no slip, a few more minor mods (electric fan, MAS, TB, headers, etc)
I think I could put it in the low...