Splash apron hole size

[CWPASADENA]

I am putting together a 31 and adding side mounted spare tires.


What is the size of the hole in the splash apron for the side mount arm?


I have pilot holes drilled that line up with the brackets on the frame.


I think it may be 1 1/2 inches but want to be sure before I enlarge the pilot holes to the final size.


Thanks in advance.


Chris W.