Great truck for hard road until about 40,000 miles; pin broke in engine and it had to be rebuilt. 60,000 miles, transmission had to be rebuilt; has a history of problems and after talking to many different owners, sellers, repair shops, the '91 F150 has a long history of major repairs. Transmission is too small for truck, which appears to be a history problem with Ford products. Universal joint had to be replaced at about 50,000, and so on. This truck was rarely used off road except to keep the 4x4 system lubed. Paint had heavy oxidation at about 20,000 miles; easily comes back with every buff or chemical oxidation removal.
Inside and outside looks. Road handling when new and after major overhaul. Large radiator.
Remove fuel pump from fuel tank. Larger transmission. Better paint. Better stereo equipment. More heavy duty parts. etc.