Unless it's a fairly new starter, I'd replace it. In '89 I think they were still using the older style strters and in the last 30 or so years, smaller, higher torque starters have come out. You might be able to get a newer, stronger starter. With the starter off, look at the ring gear on the flex plate to make sure you don't have chipped teeth on it.

As for mileage, how many digits does the odometer have? I've got an '89 Olds with a million miles speedometer. It's showing 77,000 miles with another 0 in front of the mileage. In 1992, I know Dodge was using the longer mileage units, but I don't have access to an '89 Mopar.

 

Just checked the starter and it is branded Chrysler, so odds are it's original. Didn't have time to take it off but I'll check that out soon.

Odometer only has 5 digits, reading something around 41,000. The PO thought the truck had 170k on it, but not sure where she got that number.