I just hung up the phone with Scott at Aerospace. He told me that the bolt pattern will not effect the price. However, the $635 price is for drag brakes and that price is not for Mopar. Mopar is 750 for drag brakes. They do need to have the spindle to mock up the kit to your stuff. It is now 635PM here in Florida and Scott is still working evenings. Give him a shout when you have time and he will be glad to help you. I would rather you get your pricing direct from them. That way there is no question. :)
