help with rim size


New member
Let me start off by saying, I'm new here and am lookin for a good experience! I know some people on here won't agree with what I'm wanting to do, but Im hoping to not get any negative comments about it. I'm in the process of turning a 62 4-door hardtop Catalina into a "new age" lead sled and am wanting to put 20-22 inch rims on it and have it sit as low as possible without havin to put air ride on it, yet! Anybody know how big of tires and what kind of backspacing I will need to tuck that big of a rim? Thanx in advance for any help!!!!


Staff member
measure the maximum diameter tire you can place in the wheel wells with the front control arms against the frame stops and the rear axle fully compressed against any stops or the shocks. Measure the clearance you have in front with the stock wheel and tires between the tire/wheel and any suspension components. From that determine how wide a tire you can fit. Convert the width of your tire into millimeters by multiplying by 25.5. So if you have room for a 10 inch section width, not thread, you come up with 255. Then go to a site such as and look for tires that are 255 for different aspect ratios that fit 20 or 22 inch wheels. Check the overall diameter of the tires you find to see if they will fit your first measurement. Check the backspacing of your current wheels to get a base figure. This process will provide you with a rough idea but there are so many wheels and tires available today there is no guarantee they will fit. You have to try and find a tire/wheel shop willing to work with you on checking fit.