I just purchased a 1991 Cherokee sport for $800. the body is org. with stock susp. I want to put bigger tires on it, Will 31 inch tires fit without any susp adjustment. And also I have heard that you can gain 2 inches of clearance by putting spacers in the coils and and on the rear end. How does that work and can you tell me where I can get the materials needed to make this adjustment. thanks for the help Paul