Converting NPCs from AD&D to GURPS

[Rasputin]

Originally Posted by NineDaysDead

My conversion gives Strength 10-11 as equalling ST 10, and Strength 18/00 as equalling ST 20.

It's easiest to give a straight Str = ST for D&D 3e/4e, and more or less correct too. For earlier editions, you might go with Str/2+5 = ST, with a bonus for exceptional strength. Lifting ability is not important to D&D, so don't fret about it too much.