I believe the stat begins to open at ~180* and is fully open at around 190*. I'd say you want the fan on around 190 and max @200. The exact stat specs should be in the FSM.

(aka suprathepeg, aka Sean)
89 v6 SWB truck "BLACK BEAUTY" EB valves, P&P head 30 over.
95 FZJ80. Lifted. locked and rollin on 33s (my dream machine)