I have a 1988 Scottsdale 305 4x4 manual trans.its leaking oil so bad smoke rolls from under the hood when I come to a stop.i know the exhaust it lose but could it be just that?

Yup, oil is leaking directly onto the exhaust and burning. Fix the oil leaks, normally always the valve cover gaskets, and replace the pcv valve(PCV positive crankcase ventilation valve). See can you put another PCV valve in the other valve cover and run it to the breather. The more of these lines you hook between the engine and breather, the less it will leak because vacuum is pulling all the pressure out of the engine block and crankcase so it won't push the oil out. My 383 small block has a bad front main seal, I hooked up another tube and it can't push oil out the seal. No more leaks. Hope you get her fixed soon Bro, you really look bad with all that smoke coming from your truck.