I am look at purchasing a 1997 SR5 4Runner with 146K miles. I need to do a thorough changing of all the fluids and probably plugs and AT filter.

Does anyone have any recomendations or certain things I should look for or avoid.

I was thinking of putting Lucas additives in every possible place just due to the fact they work well in quiting engines.

I was also reading in the gas mileage post to run synthetic in the diffs, what about the transfer case?

Any and all help with be appriciated.

Don't bother replacing the AT filter. It is only a metal screen and isn't really a filter. Flush the transmission, don't just drain the pan.

Air filter
PCV valve
grease propellor shafts
check brakes
Compression check
injector cleaner in the gas tank (Chevron Techron or equivalent)

Don't do the Lucas additive thing. Use 5W30 synthetic engine oil and 75W90 synthetic everywhere else (including the transfer case) if you want the best lubrication and longest possible change intervals (not in the AT of course).