quoted from toyotaoffroad.com
" Introduced in spring of 1989, Toyota unleashed an entirely new breed of 4Runner. Based on the completely redesigned line of pickup trucks, the new 4Runner was muscular and aggressive looking, but still capable of delivering the off-road performance for which Toyota's four-wheel drive trucks had long been known. The vehicle was now available in either two or four door configuration, with either a four or six cylinder engine and with either two or four wheel drive. "
If that was introduced in the spring of 1989, it was a 2nd gen and considered a 1990 even though it was released in 1989. Usually, the next year stuff is released in August unless it's a completely redesigned model - at least in the toyota world.
A guy I went to college with had a second gen 2 door 2wd 4-runner with a 22re in it! I can't remember if it was auto or manual trans though.