Originally Posted By: bullwinkle
Biggest thing I would be concerned about is the timing belt (if it hasn't been changed recently). My brother's '87 Tercel 1.5 3E, with only 27K on it, had huge dry rot cracks in it, that was the first thing I replaced when he got it, it looked like it could have broken at any time. Just about any gasoline engine oil would be WORLDS better than the SF swill they had back in '85-I would probably run 10W30 (or 10W40 or 20W50 in 100F+ desert conditions) in it, whatever brand you can get a good deal on. They don't look like that here, most of them hit the crusher long ago.
The timing belt for sure. In fact, I wouldn't worry much about the oil weight but 5w30 is the thinnest I'd go. Really, I'd be much more focused on the cooling system on this making sure hoses and the radiator looked good!