Early 1970s Ford F-150. Portland, Connecticut.

From Reid Cunningham: "It was a very rainy Memorial Day parade in Portland CT, most of the expected marchers and collector cars, especially the convertibles, stayed home.  But this minty green Ford short bed (with likely a modified engine given the sounds of the dual exhaust exiting before the rear wheels) still came to tow the American flag for the damp parade watchers.