Just bought 89 F150. First question.

I just picked up an 89 F150 long bed 2X4, straight 6 and man trans. Picked
it up for $450.00. I plan on replacing the fluids, belt, hoses, etc first
thing. Then put on some tires.

I am thinking of doing a lift kit, 2 or 3 inches. chassis not body. The
reason is to get more ground clearance for flooded roads after our very
heavy summer rains and hurricanes. The truck now has 31x10.50x15 on
aftermarket rims. Most likely 8x15. How much bigger tires can I put on with
a 3 inch lift?

Also, it has a slider rear window with a broken clasp. How can I tell if it
is a factory slider? I think it is as it has the factory rubber and looks
like the slider frame is mounted where the solid window would be.