It is small for that job, turning up the air to 150 psi didn't help much with those old impacts, IIRC that one had about 320 ft.lb. The later IR 231 was a big upgrade from that one with 450 ft.lb but still small for those lug nuts. A larger double D handle impact would probably have been used back then. The torque numbers were real back then not the nut busting numbers they use for advertising today, but the tools were still weak compared to today's.