C20 Stepside spare tire mount

[72c20customcamper]

I put the mount on today I downloaded the instructions and put it where they said . My problem is I have to put the tire on backwards if I try to mount it with the face out it hits the top rail and the rear fender . I’m guessing that the original rim would have less backspacing and be narrower? Just seems odd to me I double checked and the mount is for a 3/4 ton truck . The space between the tire and the fender well looks big too. Can’t really move it back any as the bracket would be touching the fender behind the tire