A dumb question about add a leafs

[madman 72]

hey guys this might sound dumb but I bopught some add a leafs for my blazer last weekend at a flea market. they were the front an back leafs they were still new in the boxi gave 20 bucks for them.The lable on the box said they were for the 73-up solid axle blazer. One set of leafs are really short and the others are alot longer. My question is which are the front and which are the backones. I never thought to ask the guy and the box dont say. the short ones are about 24 inches and the longer ones are about 36 inches only guessing dont have a tape as i type this. I need your alls help. I would really appriciate it.