What custom backspace would you order?
Post # 30
http://www.forabodiesonly.com/mopar/showthread.php?t=213678&page=2
Post #85
http://www.forabodiesonly.com/mopar/showthread.php?t=213678&page=2
If you want a lowered stance backspace on the front becomes critical. I think autoxcuda has it right with 5.6" backspace for a 17 x 8 rim. Note the comment about the upper ball joint. I think this depends on the specific wheel. Some 17s will clear. I did not have clearance trouble with the 18" combo I tested at the sway bar or at the front fender lip.
I purchased 18 x 7 with custom 5.125" backspace for the front. I have not done a test fit yet.
If you're not trying to go low you have more flexibility.