73 Cuda - Front Tires/Wheels: Opinions Please

[Haney]

I have a stock suspension 1973 Cuda. It has an E body width 8 3/4, springs in the stock location. It currently has 15x7 rally's up front with 235/60/15s and in the back 15x8 Rally's with 275/60/15s.

I want to put to put a set of AR Torque Thrust IIs on my 73 Cuda. For the back, I am going to use 255/60/15s on an 15x8 wheel with 4.5" of backspace. I think I am good there.

My question is mainly in the front. Will a 245/60/15 work in the front or should I stay with a 235? Should I use a 15x8 or 15x7 and what backspacing? I have read here where both are used. I am thinking a 245/60/15 on a 15x8 except with a 3.75 backspacing. Will that work without rubbing? Anyone have pictures of this set up? I also have manual steering if that would make a difference on which way I should go.

Thanks in advance...

 

[moparleo]

*
Manual steering will definitely make a difference. The 15 X7 is a factory size and obviously works. The more negative offset, wider rims and tires on front make it harder to turn when sitting still or moving slowly. More likely to rub on the rear of the inner fenders when turning. Some cars have rubbing problems and some do not. Even with the same tires and wheels. These cars were not built that precisely. Stay with the sizes you know that work or take a chance.

 

[gzig5]

I have 255/60/15 mounted on 15x7 wheels on the front and there is plenty of room to go wider. With the right offset wheel a 275+ wide would fit. But there isn't much room for a taller tire than the 27" tall 255/60/15 without catching the front fender lip.

 

[Haney]

I have 255/60/15 mounted on 15x7 wheels on the front and there is plenty of room to go wider. With the right offset wheel a 275+ wide would fit. But there isn't much room for a taller tire than the 27" tall 255/60/15 without catching the front fender lip.

Looks great! What is the Backspacing on that 15x7 front wheel?

 

[gzig5]

I want to say that is it 3.5" but I can't remember. I'll check when I get home, hopefully it is stamped on the outside surface. The rears are a 255/70/15 on a 15x8 and it needs to move closer to the spring to clear the fender lip better. That's a 29" tall tire and it really fills the well from top to bottom. These are place holders though and will be replaced with some snazzier components when the car goes back together.

 

[moparleo]

The offsets on after market steel wheels are usually different from any alloy wheel especially one piece items. He has manual steering also. More tire = more scrub and stresses on front end components when turning. Nothing s free...

Just an aside, have you contacted the Tech Dept at American Racing ? They have all the fitment info you want. Click the link for some fitment info :
About - American Racing | Classic, Custom, and Vintage Wheels
Search Results

 

[gzig5]

Looks great! What is the Backspacing on that 15x7 front wheel?

The backspace wasn't stamped, just the size, so I took it off and meausered. It looks like it is a 4" backspace. If I can get my phone to cooperate I will add a pic showing that there is still at least an inch between the tire and frame at full lock. Granted there is nothing in the car, but it never rubbed when I was driving it before disassembly.

 

[Haney]

The backspace wasn't stamped, just the size, so I took it off and meausered. It looks like it is a 4" backspace. If I can get my phone to cooperate I will add a pic showing that there is still at least an inch between the tire and frame at full lock. Granted there is nothing in the car, but it never rubbed when I was driving it before disassembly.

Wow, thanks for all the great info GZIG5! This really helps. I am thinking of a 245/60/15 on the 15x7 American Racing TTII. It has 3.75" of Backspacing. That means I will be 1/4" closer to the fender lip than you.

 

[gzig5]

That should be fine. Should be nicely balanced. I tend to go with the bigger is better theme and sometimes that can work against me. I will likely end up with two sets of wheel. a set of 18s for the track and a set of 15’s for cruising around and driving daily on

 

[Mopar Mitch]

I have a stock suspension 1973 Cuda. It has an E body width 8 3/4, springs in the stock location. It currently has 15x7 rally's up front with 235/60/15s and in the back 15x8 Rally's with 275/60/15s.

I want to put to put a set of AR Torque Thrust IIs on my 73 Cuda. For the back, I am going to use 255/60/15s on an 15x8 wheel with 4.5" of backspace. I think I am good there.

My question is mainly in the front. Will a 245/60/15 work in the front or should I stay with a 235? Should I use a 15x8 or 15x7 and what backspacing? I have read here where both are used. I am thinking a 245/60/15 on a 15x8 except with a 3.75 backspacing. Will that work without rubbing? Anyone have pictures of this set up? I also have manual steering if that would make a difference on which way I should go.

Thanks in advance...

Haney -- the major critical factor is the offset of the rim, which is the difference from centerline inwards or outwards, however, the factory would have to indicate that to make it easier for us, and also, they will never mark the rim as such. IF you measure backspacing (easier for all of us), then that will add typically 1/2" to each side, or a total of 1" to the overall rim width as measured. In other words, a 7" advertised rim... is actually 8" overall width, etc. You can safely run 7, 8, 9, 10, even 11" rim widths with the correct offset or backspacing. Another factor is the diameter of the tire... as a tall tire (~27" or taller) could then hit the fenders and inner chassis parts. Don't be afraid of folding the fender lips... very common thing being done for many cars, especially older cars like ours. Try to stay with a zero offset, or a slightly positive offset. Avoid negative offsets as they push the wheel out towards the fenders sometime too much. There are various web info sites you can learn more from... Discount Tire, Tire Rack, etc.

 

[gzig5]

To pile onto the good words from Mitch, I've learned a lot by playing with the various offset calculators which visually show you how a different wheel or tire size will affect your fitment and sometimes compare directly. Some are better than others. The attached is kind of basic, but that site has several other functions, including a listing of tire sizes and what tires are available in them.
Wheel Offset Calculator
Tire Size Comparison
Tire Size Chart

 

[Rons340]

The offsets on after market steel wheels are usually different from any alloy wheel especially one piece items. He has manual steering also. More tire = more scrub and stresses on front end components when turning. Nothing s free...

Just an aside, have you contacted the Tech Dept at American Racing ? They have all the fitment info you want. Click the link for some fitment info :
About - American Racing | Classic, Custom, and Vintage Wheels
Search Results

The video they have posted is very informative as to correct measuring techniques.

 

[Rons340]

Thanks to everyone that is on this thread. I am sizing up my 1972 Challanger for her first set of wheels and tires.
I benefited from each of your posts to better understand tire sizing and especially backspacing.
Thanks again to all!

 

[Rapid Transit]

I have a stock suspension 1973 Cuda. It has an E body width 8 3/4, springs in the stock location. It currently has 15x7 rally's up front with 235/60/15s and in the back 15x8 Rally's with 275/60/15s.

I want to put to put a set of AR Torque Thrust IIs on my 73 Cuda. For the back, I am going to use 255/60/15s on an 15x8 wheel with 4.5" of backspace. I think I am good there.

My question is mainly in the front. Will a 245/60/15 work in the front or should I stay with a 235? Should I use a 15x8 or 15x7 and what backspacing? I have read here where both are used. I am thinking a 245/60/15 on a 15x8 except with a 3.75 backspacing. Will that work without rubbing? Anyone have pictures of this set up? I also have manual steering if that would make a difference on which way I should go.

Thanks in advance...

I have a 73 Cuda with 7" wheels up front with 245/60-15 tires, no problem. I do not recall the backspace on the wheels.
I am running 8" wheels with 4.5" of backspace with 275/60-15 tires with no issues there either.

 

[DustyDave]

Haney -- the major critical factor is the offset of the rim, which is the difference from centerline inwards or outwards, however, the factory would have to indicate that to make it easier for us, and also, they will never mark the rim as such. IF you measure backspacing (easier for all of us), then that will add typically 1/2" to each side, or a total of 1" to the overall rim width as measured. In other words, a 7" advertised rim... is actually 8" overall width, etc. You can safely run 7, 8, 9, 10, even 11" rim widths with the correct offset or backspacing. Another factor is the diameter of the tire... as a tall tire (~27" or taller) could then hit the fenders and inner chassis parts. Don't be afraid of folding the fender lips... very common thing being done for many cars, especially older cars like ours. Try to stay with a zero offset, or a slightly positive offset. Avoid negative offsets as they push the wheel out towards the fenders sometime too much. There are various web info sites you can learn more from... Discount Tire, Tire Rack, etc.

The only problem with this is — you can only buy what is offered. Mag wheels today are only offered in certain backspacing. For instance, I want to put some Keystone wheels on my Cuda — but all either jegs or Summit offer is like a 3 inch backspace with a -3 mm offset on a 15x6 for the front. I have no idea if that will work for me or not. I plan on keeping the same tire size which is p215/65 on the front

 

[Rons340]

I would getting away from those places and check with a real tire and wheel store. They have access to a lot more sizes than just what they stock. I will put a link to the store that I got mine below. They have any offset and width combo you want.
Also, They came to my shop mounted, balanced, nitrogen filled, with center caps, lug nuts, and wheel locks, all on a pallet and ready to mount on the car. Free Shipping! I doesn't hurt to check!

Performance Plus Tires
Custom Tires, Custom Wheels, Wheel and Tire Packages, Chrome Rims for your Car, Truck, or SUV from Performance Plus Wheel and Tire

 

[Mopar Mitch]

The only problem with this is — you can only buy what is offered. Mag wheels today are only offered in certain backspacing. For instance, I want to put some Keystone wheels on my Cuda — but all either jegs or Summit offer is like a 3 inch backspace with a -3 mm offset on a 15x6 for the front. I have no idea if that will work for me or not. I plan on keeping the same tire size which is p215/65 on the front

DustyDave -- you'll be amazed what is available in different rim sizes, offsets... etc. Just be flexible with the styles. Realistically, you could get exactly what you need and want... but have to be willing to spend the money on custom rims. Search and study some more.