I've been running 87 Octane with no issues with putting at least 5K miles on it so far. Not to say its good to go but from my experience it works very well. The engine is very peppy on the low to mid range. My SWB laughs at 33's but I have yet to load it down with gear and heavy duty bumpers and other such stuff that will eventually slow it down some.

99 Gen 2.5, fixing blown head gasket
89 SWB- 33's, ARB Front locker, SR rear locker/axle, SR F brakes, winch, WST Offroad Armor all Around, 2.85 Aussie T-case Gears (SOLD)
Sold: (2) 95 SR's, 86 SWB, 90LWB, 91 LWB
-Can Change a timing belt in my sleep..