I am confused I thought I had the 8.8 in my truck and when I hat to replace the rear wheel seal and bearing the 8.8 were too big I needed the parts for a 7.5 but need a new diff cover and the 7.5 was way too small so I am confused about the axle I have. The truck is a 94 Ranger 4x4 4.0 5 speed.
You've been victimized by the malprogrammed chain store computer system (this happens often. Few people at those places know anything that the computer doesn't tell them, and no one else seems to care the systems are loaded with major errors
).
You do have the 8.8" axle for sure, but bearings & seals (and possibly axle shafts too) will need to be bought as for a 7.5".
There's a similar fiasco with front brake rotors, seals and bearings on '91-'94 trucks, they'll ask you what gear ratio you have or if you have the D28 or D35. In your case you're ok here (D35), but for anyone who says "3.45 gears" or specifies "D28", they'll get parts for the older D28 axle that went completely out of production in '90, when ALL of these parts are 100% the same no matter what axle or ratio is under these years.