I picked the owners maual out of this 94. It list 91 premium for the fuel on this one. This is probably on Franks thread , but just incase , here it is.
Just got a Chilton on Diamante for the ol' library. Gonna see all the different setup for ECU/Emmission wiring to see if I can use the Dia electric system. I doubt it though cause I don't know how to put the MAP on my plenum.

dave h.
'89 Raider V6 5spd;Aisin Hubs;; Gen2 LS: frt. brakes, rear coils;U.C.arms;R.trailing arms;idler arm; rear LSD axle w.disc brakes ;2 battery system for Dog's fan; relocated ECU; custom bumpers;J.Baker receiver;Conferr roofrack; t-bar crank.