17. The Grand now has a very comfortable luxury-vehicle performance ride, and I am extremely happy with the JKS and ARB suspension components. The track width on the ZJ went from approximately 58.5 inches to 62.5 inches. I used the factory Wrangler JK wheels and the backspacing is 53/4 inches, which brings the wheels and tires back under the vehicle. The tires protrude only about 11/2 inches beyond the wheelwells. The wheelbase is now 108 inches, compared to the factory 105.9, and I can definitely notice better stability.