For the years that you are looking at, unless it's pre 74 where you could get a BB, the L-82 is the best your going do. These cars aren't real desireable YET, but I guess they will be next inline. A '75 convertible L-82 (last conv.)will be highly desireable someday and sortof already are, if you see any of those while your looking.
I
personally (jmo) would stay away from 76,77,78. According to my dad, who owned a used dealership at that time, said they were the worst vett ever made with the exception of the '84.
Again just my opinion . If you find one you like get it!!! They are old enough that any of them should only go up in value.
A 1982 L-82 ( i think they offered L-82 til'82) seems like it would be desireable soon. Last of the L-82s? and last of the body style.
A 1983 is ultra rare if you see one of those.