Hi.
I am in search of the proper size SS Cragar wheels for my bird. The car came with 14x6 wheels. I bought new disc brakes for the front and new drums for the rear to fit the 14" wheels when I thought I was going to keep them but with my restoration 70% done, I think the car is going to look too good for the stock wheel. The rear will be 1" lower and the front 2" due to the Hotchkis front spring/rear leaf spring parts. I wanted a little wider tire in the back. I was thinking 15x6 size but the offset thing has be baffled! I figured the best people to ask are the ones who already have it! Jegs was no help when I called them other than to buy their $70 tool. Any input would be helpful. Tire size suggestions would be great too since I may have to do a lower profile!
Thank you.

I run 17's so can't really help (lower profile tires use wider rims).

Anyway, between F-bodies it's been found that there is some variance. So some cars can get away with a little more tire than others (this is usually in the case of 255s vs. 275s). This can be due to manufacturing tolerances and sometimes simply due to previous body repairs. The best thing to do is measure your specific car.

If you don't want to buy the tool, you could use your existing rims as a basis to see how much clearance you have. A quick search should tell you how to calculate your current backspacing and with a little math you should be able to get the new spacing with a different rim.

Christine, yellowbird posted this site to clarify sizing rims. The second site is for tire size comparison.

https://www.rsracing.com/tech-wheel.html

http://www.miata.net/garage/tirecalc.html

The important things to consider are the backspace on the rim and tire size. 15" rims are ok to use, but keep in mind not getting a tire to tall or wide. With the '67-8 'birds the fender and tub size are less forgiving for bigger and taller tires than the '69. Also, if you’re lowering the car this will limit you further.

I would stay with the same backspace as your stock rims. If you want to go to a wider tire and rim you will want a deeper offset. As to how much, other '67-8 owners will have to key in. With wider tires wider rims are needed to avoid sidewall bulge. Generally an inch wider rim is required for a wider tire.

In my case, I'm running P225/70R14 tires on stock 14x7 Rally II's on my cammer. These tires have a diameter of 26.4". My cammer isn't lowered; and I've experienced fender rubbing on steep driveway aprons and ramps with the wheels turned hard. I wouldn't put this size tire on my lowered convertible.

IMO a tire size with a 25.5" - 26" (aprox) diameter will be a safe bet being your going with a lower stance. This would calculate out to a P215/70 R14 or a P195/70R15. With a wider tire perhaps a P245/60R14 or a P215/60R15. But being a '67-8 you may have problems with wider tires in the front. If you are going to mix tire size from front to back, try to keep the tire diameter close.

I hope I haven't given you info overload. Play around with the web links and you'll get a better picture of what I tried to convey.

Hi Christine,
One thing to rethink..... You said,"I think the car is going to look too good for the stock wheel."

That's not really possible. Now, the stock wheels could look too good for some cars.....
Had to say it.....

Rally I maybe. Plain steel, not really.

What about II's? Not even worth a consideration Mike?

I thought the Rally IIs didn't come out until 1968?

if there is a tire barn or other tire place in your area they should have the tool you would need to size the tire for you! they should have no problem doing this and if they cant, try finding a place that sells aftermarket wheels. they will have all info on this. if not they rnt worth a broke @!@k!

'67 was the first year for the Rally II. You could order either Rally I's or II's