Check for rust over the wheel wells and rear frame rails. If it runs rough it can be several things, vacuum leak, manifold leak, carb problems, fuel filter, fuel pump, so if it runs rough, see if you can diagnos before you buy. Electrical problems don't seem to be a huge issue with these trucks (other than fusible links and some wire that runs to the back of the truck through the rear quarter, but I can't remember what that is about right now). Vacuum leaks are the big issue, if the vac hoses haven't been replaced, plan on placing an order with McMaster Carr eventually to replace all the vacuum hoses, unless it's desmogged, then much less of an issue.