Just picked up an 84 4x4. Truck is in great cosmetic condition but the engine has me a little worried. There seems to be a lot of valve noise. I have checked the valve adjustment and it appears to be ok. The previous owner replace the cam, and cam gear and said that the bottom end was done about two years ago although, I don't believe this to be the truth. The head and valves may be original but I can't tell. Any ideas...anyone....Bueller,