Before 76, the front and rear were 1.75 " wide and same length I think. In 76 they went 2" front and 2.5" wide in the rear and were different lengths. There are different front springs for engine size and different rear springs for hard or soft top.....then each combo comes in standard, Heavy duty (towing) and soft ride. So there is a ton of combinations. There are numbers on the shortest leaf in the pack that tells what it is....