It sure does make sense! Also your Polara sounds very nice!! I hope I did not come off to gruff and am sorry if I did! A 29 inch tall tire is in reality 1 inch taller inside the fender well than a 27 inch tire if that makes sense, and the rear end of your car is 1 inch higher off the ground! To tall and your headlights will need to be adjusted up to compensate, minor problem but noticeable at night. Looking at it that way measure straight up from the widest part of your tire to a clearance problem probably the outer fender well and figure the maximum height you can go. Also don't forget to compensate for the travel of the suspension. Mike posted a formula that will get you were you want to be with tire height but be sure to check clearance so the new tires don't rub. Herb 1956 Plymouth Belvedere 361 1959 Coronet 326 Poly 1963 Fury 2D/HT 6.1 1963 Sport Fury Convertible 361 1970 Challenger RT 440 1999 Durango SLT 5.9 2006 300-C Heritage 5.7 2008 SRT-8 Magnum 6.1 St. Louis, MO. http://1962to1965mopar.ornocar.com/mmo42009.html -------Original Message------- From: Layne Grissman Date: 6/10/2009 11:52:22 AM To: 1962to1965mopars@xxxxxxxxxx Subject: Re: Tire Sizes and how to calculate ${top_text_ad} Wow, Good post. And I will agree, too many of the "Car and Tire" Shops out there depend too much on the computer... As for the 3.91's, well, we got the car with the 3.91's in her, however it was not original, as the person we bought the car from many years ago made some very significant changes to the car. This one had a 413 in it from a '63 Imperial, so we built it up...It was a Max Wedge Block casting...We bored it over .030, and added dual fours to her, new cam, new Edelbrock Performer RPM heads and Doug's Headers to her, so she will be a performer to an extent...., it was originally a 318....as well as the 489 case and 3.91 gears, which from what we know were originally 3.23's....non sure grip.... This car is not stock and we are not worried about the originality of it. Things would have been easier if we only went with original. We are not tubbing it out, we are not making body changes, and we are keeping it as close to stock as the day we got it, if that makes any sense. We're just trying to work with what we have, hence the reason I asked the question. We were thinking about going with 29" tall to try and compensate a little but I wanted to be sure and get a little more specific on exactly what we needed... This is why we are trying to figure the proper size. Hope that all makes sense... Layne [Non-text portions of this message have been removed] ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html. This email was sent to: arc.6265@xxxxxxxxxxxxxx u/?bUrDWg.bSONJP.YXJjLjYy ?p=TEXFOOTER