I want to put 37x13.50/18's on a 07 screw with a 6'' procomp and 2.5'' spacer and block kit. How much rubbing will I have and what backspacing would I need on the rims for the tires. I would be ok with minor rubbing at 85-90% turn and above as it will not be my daily driver.

Also if anyone could post pics of 04-08 screws with 6'' + 2'' kit with 37's I would appreciate it.

 

You may be able to fit those using an 18x9 with at least 5 inches of backspacing, but it will be tight.

 

so my offset would be +5?

 

No, the backspacing would be 5 inches (or more). I'm not sure what offset that translates into for an 9 inch wide wheel.