Just another topic I know squat about:o ...but I've been reading and reading..

I'm strongly considering getting 17" wheels for my 69'. I like the look of this combo:

Front - 17x8 245/45/17
Rear - 17x9.5 275/40/17

* I was told that I need 5" bs for the rear*

My question is this: What is the benefit of using 9.5" wheels in the rear...if you can put the same size tire (275/40/17) on an 8" wheel? I mean, it will basically look the same won't it? Also, I can't get 9.5 wheels for the brand I like, as they only have 8 and then go to 10.

Look at an 8" wheel next to a 9.5" wheel and you will see 2 of the reasons. One is that the 9.5 will have more dish to it and look deeper. The other is there will be less bulge in the side wall. Lets say that 275 tire has an 11" section width. On an 8" wide wheel you will have 3" of bulge split between each side of the wheel that's 1.5" on each side. On a 9.5" wheel the bulge is only 1.5" or .75" on each side. The less the tires sidewall bulges from the rim to the tread the better the handling...

I also believe you want 5.5" back space on a 9.5" wheel, that's what I'm running...

Check this link to compare wheel widths with tires on them, most list teh wheel and tire sizes. http://www.camaros.net/forums/showthread.php?t=100853

Wow! You need to do a search on this. There is tons of info to confuse you more. The reason you want a wider wheel with that size tire is the footprint will be better. Look at the recommended wheel width for that size tire. The tirerack is a good place to see that type of info. Now the hard part. You want a 9.5" wheel with a 5.5" backspace. If you have a stock width rear that .5" will be the difference of the tire rubbing the outter wheel lip and cutting up the edge of the tire. Several factors come into play with these cars and they are ALL A LITTLE DIFFERENT. So be careful. If the car has repo 1/4s you may have a little extra room. Some people have gotten 10" wide rear wheels to fit. They use 5.75" of backspace in most cases. To get these to fit you have to be creative. You may have to trim or roll the outter lip and/or beat in the inner wheel house to gain a little extra room. Ride height and disc brakes effect clearence also. My suggestion is to find a wheel in 9.5" with 5.5" of backspace that you like. Or you can just play it safe and go with the 8" wheel and use a 255/45-17 tire. That will work with NO issues. I know I just confused you more instead of helping the situation but others will jump in and maybe clear things up a little better than I did.

Look at an 8" wheel next to a 9.5" wheel and you will see 2 of the reasons. One is that the 9.5 will have more dish to it and look deeper. The other is there will be less bulge in the side wall. Lets say that 275 tire has an 11" section width. On an 8" wide wheel you will have 3" of bulge split between each side of the wheel that's 1.5" on each side. On a 9.5" wheel the bulge is only 1.5" or .75" on each side. The less the tires sidewall bulges from the rim to the tread the better the handling...

I also believe you want 5.5" back space on a 9.5" wheel, that's what I'm running...


I see! Perfect explanation, Dennis, thanks. Makes a lot of sense about the handling with the bulge etc..

Are you actually running the exact same combo I mentioned? So a 5.5 is what's needed, eh? I actually asked a tire dealer today...he called American Racing and 5" is what they told him? I really like the Boyd C tires a bit better than AR TT2's, but I can't get 9.5 for the rear. TT2's come in 9.5 though. I can't tell by your pic what those are on that beautiful ragtop.

Wow! You need to do a search on this. There is tons of info to confuse you more. The reason you want a wider wheel with that size tire is the footprint will be better. Look at the recommended wheel width for that size tire. The tirerack is a good place to see that type of info. Now the hard part. You want a 9.5" wheel with a 5.5" backspace. If you have a stock width rear that .5" will be the difference of the tire rubbing the outter wheel lip and cutting up the edge of the tire. Several factors come into play with these cars and they are ALL A LITTLE DIFFERENT. So be careful. If the car has repo 1/4s you may have a little extra room. Some people have gotten 10" wide rear wheels to fit. They use 5.75" of backspace in most cases. To get these to fit you have to be creative. You may have to trim or roll the outter lip and/or beat in the inner wheel house to gain a little extra room. Ride height and disc brakes effect clearence also. My suggestion is to find a wheel in 9.5" with 5.5" of backspace that you like. Or you can just play it safe and go with the 8" wheel and use a 255/45-17 tire. That will work with NO issues. I know I just confused you more instead of helping the situation but others will jump in and maybe clear things up a little better than I did.

No Jack, you didn't actually confuse me more, lol. That's great added info, and I thank you for it! Man, if you knew how many threads I've read here...and how many pics I've looked at in the sticky here....it seems that my desired combo is a pretty good set for my car. My car does have one rear quarter replaced, but my car currently sits too high, too. I've currently got 255/60/15's Rally's on the rear, and I've got nearly 2.5" of space to the center arch.