230k isn't bad at all if the engine has been serviced regularly. My Dad's '86 2wd has over 300k(all original miles) on it and the engine compression is still in the 150psi range. Since the '89 is priced in the KBB range I would do a compression check and valve adjustment(if needed), then recheck the compression. IIRC, the comp range is iether 125-175psi or 135-175psi for the 22r(e). If the compression is anywhere above 150psi you are good for sometime to come. If you don't want to do the check yourself, take the truck to a Toyota dealer or import mechanic who is experienced with Toyota's and have them inspect it. It shouldn't run you more than $100-150, and would help your peace of mind, if you do decide to buy it.