Ive asked this a few times already with no luck on responses and I need to order rims in the next few days..could somebody PLEASE shed some light or guidance on what kind of backspacing I should be looking at on a 17x8 rim on a 66 lesabre?
I have to guess that the reason you haven't gotten a response is because there aren't many people using 17x8 wheels on a `66 LaSabre. My suggestion would be to measure what kind of fender clearance you have. I have always used a piece of string with a 1/2" nut or something equivalent in weight tied to one end of it, then tape other end of the string to the fender above the wheel opening, let it hang with the weight of the nut on it, then measure in to the drum. You can use this method to measure both back and front spacing. Know the dimensions of the tires you plan to use, not just the tread width but also height and the cross section width and you should be able to determine what will fit on the car.
You can really answer your own question with a little more information. First figure out what size tire you intend to run. Bear in mind that your best option is to size the tire as close to stock height as possible. This will look the best, and not affect your speedometer calibration, or rear gear ratio. Using a 17" rim means the tire will need to be wider and have a smaller aspect ratio (shorter side wall) Find out what the back spacing is on the stock wheel, and how wide the stock wheel is. If the stock wheel is 6" wide, and you want to use an 8" wheel, you will need an additional 1" of back spacing to keep the tire centered in the wheel well. Take some measurements as Golden Oldie 65 suggested, and see if you have the room to do this. Good luck.
Can't comment directly on a '66, but when I was planning on going with 17's, I was going to run 17x7's with 4in of BS in the front and 17x8's with 4.5in of BS in the rear. It wouldn't be that difficult for you to grab a tape measure and check it out for yourself...
Thanks for the replies...I should have mentioned that im trying to do all this while the car is 100 miles away, but maybe I can have my dad go over and try some measurements. I have been trying to find out what the stock rim size was (cause it had cragars on it when I bought it, which I think are 15x7's) and what the stock backspacing was, but i havnt had much luck finding anything online. As for the tires I guess I have a question there too..Is 225 not wide enough for the 8 inch rim? I was thinking either 225/245 x45x17....
If I may make a suggestion. Anyone who owns a classic car should make his or her first purchase, a copy of the Factory Chassis Manual. It has all the basic specifications for the car, and is a valuable resource when working on that car. They are even available on CD ROM here. http://www.gearheadcafe.com/servlet/the-508/1966-Buick-shop-manual,repair/Detail The information you seek is there for sure.
Good call on this, I forgot that i actually have the chassis manual for it..so I dug it out from where it was and if Im reading it correctly its telling me that the standard rim size was 15x5.50? With the option for 15x6...However I have not found the backspacing in here yet, so Im half way there...Im really hoping the stock was 4 so I can accomidate the rims I want.
Hopefully, someone with a 66 LeSabre can measure the back spacing for you. That would give you a starting point.
Before spending big $ on wheels I would spend a bunch of time with the car and some measuring. I would never try to order wheels based on a few measurements.... Start by measuring the backspace of the current wheels and see if they are centered in the wheel well. Make measurements of the front wheel at full steer each way so you can tell the low clearance areas. If you are using a wider wheel just calculate what the backpace would need to be in order to center the wheel in the wheel well. To keep it simple I would use a tire diameter the same as stock to keep your fender clearance. Measure twice cut once....:beers2: One last tip, the 16" tires cost less and you could get a stock diameter tire with a nice look IMHO.
Thanks for all the help everyone...I had my dad go over today and found that the cragar is a 15x7 with 4 inch bs...So I should be good to go with 4.5 bs on the 17x8. Im planning on ordering these tonight and also the tires. I did call a tire shop and they said I should be ok running the 225 for the 8", and I think Im sticking with 45 for the tread wall. Thanks for the replies
I think you should consider a bigger tire. Not sure what the stock tire height was, but it is a good bet that it was at least 27". A P245/45R-17 is only 25.68" tall. That will throw off your speedometer as well as your rear gear. It will also not look right IMHO.
Hmm how about a 55? As you can probably gather Im not very familar with how that number converts in actual tire height in inches..
It's very simple. All you need is a calculator. Our tire sizes are a mixture of metric and English measurements. Taking the P245/45R-17. P is for passenger car tire. The number 245 is the section width of the tire in MILLIMETERS. That is the measurement from sidewall to sidewall with the tire inflated on a standard rim. The 45 is the aspect ratio. It tells you that the sidewall will be 45% of the section width. R is for radial tire. 17 is of course the rim height in INCHES. What I do is convert the rim height to millimeters, then add the sidewall above the rim, and below it. There are 25.4 mm in one inch. 17 X 25.4 = 431.8 mm. The sidewall will be 45% of 245 which is 110.25 mm. Multiply that by 2 to get 220.5 mm. Add that to the rim height to get a total tire height of 652.3 mm. Divide that by 25.4 mm/inch, and you get 25.68" As you can see, if the aspect ratio remains the same, and the tire width is increased, the tire will also get taller. Using larger aspect ratio with the same tire width will also make the tire taller. Going with a 55 aspect ratio and the same 245 section width will result in a tire that is [245 X .55 = 134.75] X 2 + 431.8 =701.3 mm / 25.4 = 27.61". I don't know if there is such a size available (P245/55R-17), but that might be a better choice for a car like the LeSabre.
Awesome, thank you so much for all the info. A 245/55/17 isnt available in the tire I want, but a 235/55/17 is and if my math is right thats about 27.2, I'll have to do the math on a few more sizes.
That is correct. Now you choose a size that is best. I'm not sure what the stock tire height was on a 66 LeSabre, but try to stay as close to that as possible. I'm sure it is at least 27". My sources say the stock tire was a 8.45-15. I've been trying to find out what that converts to in today's sizes. Tires in those days had an aspect ratio around 78-80. That would mean that tire is likely 28" + See what you can find out and get as close as possible.
Yeah I checked the chassis manual and 8.45-15 is what I came up with also...and your right, trying to convert that into modern terms is tough. I do know that the car currently has 225/70/15 so 27.4, and the tire Im looking at is close at 235/55/17 (27.2). Not sure if the tires on there now are correct but thats what Ive been driving on the time Ive had the car.
Well, If those tires fill the wheel well, and look OK to you, sounds good. But, how about a P255/55R-17? They are28" tall. I'd look for those. http://www.sears.com/shc/s/p_10153_12605_09589165000P http://superbuytires.com/tires/255/55R17 http://discounttires.com/product_de...=963&optionsArray=&packID=0&maintainOptions=1 http://tire-finder.com/bridgestone-p255-55r-17-tire
Judging from what neighbors the 8.45-15 on the charts on most sites Im guessing its probably closer to 28 than 27, like the 255-55-17 would be. Unfortunetely the tire I want (which I can finally post up) doesnt seem to offer anything exactly at 28 (atleast from my math so far). Heres the tire that Im really sold on : Im really in love with that tread pattern and havnt found any other tires I like as much...and they got pretty good reviews and Ive always been a fan of bfgs...and theyre going on these rims: MB old school gunmetal...so Im gonna try to find something closer to 28 on that. But if not I'll be happy atleast getting 27.2
