1983 ford f150 5.0l problems

I justg bought this truck. it runs a little rough but nothing out of the ordinary for the year. however when you put it in reverse it stalls. or if you try to idol in gear while wrm it stalls after time. I am planning to do the basic tune uo tommorow but I need to know if there are any particulars with this year of truck I should be looking for.

Look for a vacuum leak. Hose, carb base or intake manifold.