Can anybody tell me what the bolt circle is on my new 392 ? Will changing the tire size screw up the computer ? I want to run the car a couple of times, and possibly use a Drag Radial rear tire ! I was told that changing the tire sizes from stock (Front and Rear), and then back to the original 20" tires would screw up the computer ? Or slick' on the rear, and skinnies on the front ! The car is an auto, w/3.92 gear .....Thanks.......John