Re: 1994 ranger 392v
Don't jump into buying that boat, be very skeptical. IMO bass boats as a group are less well maintained than most any other type of boat. That's not saying that this particular boat wasn't well maintained, but over the years I've seen far more bass boats sitting in driveways uncovered than any other type of boat. I'm currently rebuilding a bass boat (not a Ranger though) - the previous owner swore up and down that the boat was in great shape. (I actually just bought the boat for the engine, my original plan was to scrap the boat.... there were soft spots in the floor and there was a lot of motion in the transom when you pushed/pulled on the engine.)
Look very carefully at the transom for any sign of the fiberglass skin separating near the top edges, it does that when the wood inside gets wet and expands. Push and pull HARD on the engine as you're watching the transom for any sign of movement, the lower unit itself may move a bit because of flex in the engine mounts but there should be zero motion of the engine mounting bracket. Look for signs of poorly sealed screw holes in the transom where the pitot and transducer are mounted. Often times silicone was used to seal bolt and screw holes and it probably won't still be doing it's job on a 20 year old boat.
Look at the way bilge pumps are mounted, if there are screws going into the hull (actually they'd be going into the core - I'm pretty sure that hull is going to have a balsa core) that's a sure sign of trouble - over time water gets into the core and rots it.
Look at as much of the wiring as you can see. Is it neat and tidy, or is it a tangled mess of redneck engineering?
Good luck.