vin # ???

[shanetch]

The vin number on my truck is CKE182S105116. I have figured the production number on the last six numbers. The problem is my cab doesn't have the rear view mirror spot above the windshield. So I think I have a 72 cab, but I don't have the door pillar release valve above the vin #. I know it was made at the St. Louis plant because of the S. The E stand for a v-8. The 1 stands for half ton. The K for 4x4. It's the 8 and the 2 that I have a problem. If the 8 is the year then what of the 2. It is either a 72 or a 68. Do the 4x4 have the CK like mine? Or just the K. Any help would be appreciated. I know that a 4 is a stepside and a 34 is a fleetside.