VIN should be on the side of the cowl on the passenger side. It will be covered by the rear edge of the hood and can only be seen with the hood open.
The bigger truck sounds like it will be either a 2&1/2 ton or bigger (tandem axle usually means 5 ton.
The 3/4 or 1-ton will have differences in length of bed and size of brakes. The GVW will be 8,800 on the 1-ton and it will have a 134 & 1/2 wheel base compared to the 125 & 1/4 for the 3/4-ton which will have a GVW of 5,800

There is enough good in the worst of us and enough bad in the best of us that it does not behoove any of us to criticize the rest of us.
-
-
Be yourself. If you are ever lost, It will be much easier to find yourself if you know who you are!