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I have a 1968 Camaro Convertible that I've installed a Hotchkis TVS suspension kit, 2" lower in front and 1 1/2" lower in the rear. Can anyone guide me on front tire sizes? I'm planning on 15 x 7s with a 4 1/2" backspace. I tried 15 x 8 with a 4 1/2" backspace with 235/60/15 and experienced tire scrub when hitting bumps and trire rub on the fender wells under hard turning.
 

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My 68 (lowered similar to yours) has 18x7 (4.25 BS) upfront with a 225 series tire and I have zero rubbing issues. 235 series tire is going to be a little wider (10mm). Also with your 4.5 BS your tire will be a little deeper or closer to the inner well. It's better to have too much BS than not enough as you can always add a spacer and bring the tire/wheel outwards. Not much you can do with too little BS. My guess is your ideal BS should be 4.125 but once again you can turn 4.5BS into 4.125BS by adding 3/8 spacer which is very common.

Couple threads you may want scan:
http://www.camaros.net/forums/showthread.php?t=221929
http://www.camaros.net/forums/showthread.php?t=215123
 

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Your 235/60 15's should fit just fine with a 4.5 inch backspaced wheel. Go to wheel and tire forum or do a search and you will find many threads discussing this as well as seeing pics of wheel/tire combos.
 

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Thanks guys! Great information. I'll let you know how everything come out....maybe some phots as well.
 

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I have same suspension on my 68 vert plus I added 1" drop blocks in the rear. I have 15x7 TT-D's with 3.76BS and 225/60's up front and 245/60's in back. Next time I'll go to 255's in rear as there is still some fender room to fill.
 

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You can run several different back spacing's but if you want to center the tire in the wheel opening of a 1st gen you'll want a plus 6 offset to allow the widest possible tire. On a 7" wheel that equates to 4.25" backspacing, for other wheel widths check this chart...

 

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I have 255-60-15 tires on the back of my 68 with no rubbing issues.
 

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You can run several different back spacing's but if you want to center the tire in the wheel opening of a 1st gen you'll want a plus 6 offset to allow the widest possible tire. On a 7" wheel that equates to 4.25" backspacing, for other wheel widths check this chart...

Hey Dennis, please explain why the plus 6 offset versus any other offset. I don't have a clue on this one but would like to know for future. Thanks in advance.
 

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Matt - it's really just how the 1st gen was designed. The '69 Z/28 came with a 15x7 4.25" backspacing, both front and rear and that equates to a 6 offset (see chart). It's also fairly common knowledge that a 9.5" wide wheel with 5.5" backspacing (also a 6 offset) is the widest wheel to fit the same rear wheel well and an 8" wheel with 4.75" backspacing (also 6 offset) is the widest to fit the front.

In conclusion, any wheel with a 6 offset will pretty much center the tire in the 1st gen wheel well. This is strictly talking a stock Camaro with respect to hub and axle flange position.
 

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Hi,
Remember that the tire width as well as the circumference will differ if you put the tire on another rim width than the "design rim width".
In my case I have a 245/60-15 on a 15x8 rim. The 245/60 tire is designed for a 7" wide rim. If you put it on a 8" wide rim the tire will be approx 10 mm wider (5 mm per half inch of rim) and that will also affect the overall tire diameter. For each 1/2" wider rim (compared to the designed rim width) the tire diameter will be 5 mm smaller.
For those of you who are interested I have a tire calculator on my webpage, see link below.
http://goto.glocalnet.net/c67/calcwheel.html
/Mikael
 
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