Question about replacing 15x7 wheels with 15x8

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69GT

69GT

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My car currently has 15x7 rallys with 4 1/4" backspacing and 255-60 tires on the rear. I want to get some aftermarket wheels that are 15x8 and still use the 255-60 tires. In doing so I want to keep the tire in the exact same position in the wheelwell as it is now. My thinking is that to position the tire in the same spot in the wheelwell as it is on the 15x7 with the 4 1/4 BS that I will need the 15x8 to have 4 3/4 BS. I just figured that dividing the extra 1" inch of rim width in half (half to the inside and half to the outside) and adding it to the 4 1/4 BS of the 7" rim would put me at 4 3/4" BS on the 8" rim. Does this sound right?
 
It all depends on how close your tire is to the leaf springs now. If you increase the back spacing,chances are it will hit the Springs. Just my Opinion.
 
yes i believe you are correct. I wonder if you can find that back spacing. I know 4.5 is common with 8 inch wheels. I put 8 inch with 4.5 back spacing and a similar width tire on a 69 barracuda and it rubs the wheel well and not even close to the spring
 
Your thinking is correct. Increasing the backspacing by one half of the increase in wheel width should keep the tire in exactly the same place in the wheel tub. The increased wheel width can make the tire section width a bit wider, making it come a little closer to the outer portion of the wheel tubs & the leaf spring. If you have a lot of clearance on each side you snould be fine. I have run tires as close as 1/4" to 3/8" from the spring & only ended up with a shiny spot on the spring. I would try to stay at least 3/8" from everything, & more is always better. I read somewhere that you should have half an inch.
 
FWIW, I have 15x8 with 4.5" back spacing and 255/60 tires on the back of my 68 Barracuda. I am about 1/2" way from the tire rubbing the spring but about 1 1/2" from the tire hitting the wheel well to the outside.

Using an 8" wide rim with 4.75" back space rim is going to put you at 1/4" away from the spring which could allow the tire to rub the spring during cornering.

If I could do it over I would prefer the 15x8 to have 4.25" of back spacing.

From your user name I am assuming you have a Dart. Dart wheel wells are not a big as Barracuda wells so you may have other clearance issues.
 
Hi Folks,
I need help & suggestions in replacing my original rims on my 69 Barracuda. Please help me in the following issues:

-what is the best looking wheel for 69 Barracuda?
-what is the best size wheels & tires (rear & front) that will look nice and does not make any kind of problem? Thanks

Barracuda69-Fastback.jpg
 
Dhow said:
Hi Folks,
I need help & suggestions in replacing my original rims on my 69 Barracuda. Please help me in the following issues:

-what is the best looking wheel for 69 Barracuda?
-what is the best size wheels & tires (rear & front) that will look nice and does not make any kind of problem? Thanks

Barracuda69-Fastback.jpg
Click to expand...


Funny…. Many people pay a couple thousand to get those wheels on their 69.
 
dgc333 said:
FWIW, I have 15x8 with 4.5" back spacing and 255/60 tires on the back of my 68 Barracuda. I am about 1/2" way from the tire rubbing the spring but about 1 1/2" from the tire hitting the wheel well to the outside.

Using an 8" wide rim with 4.75" back space rim is going to put you at 1/4" away from the spring which could allow the tire to rub the spring during cornering.

If I could do it over I would prefer the 15x8 to have 4.25" of back spacing.

From your user name I am assuming you have a Dart. Dart wheel wells are not a big as Barracuda wells so you may have other clearance issues.
Click to expand...

So you saying my freind, if I go with the Torq Thrust II Wheels, it would be better to have 15x8 4.25 back spacing without any knid of problems?
What about the front - would be the same size or 15x7 would be better?
** all am looking for is to have my car look more sport with the space between tires and panel filled !
 
Yes, a 4.25" back spaced 8" wide wheel will be centered in the wheel well better allowing for a wider tire. BUT! my Barracuda has bigger wheel wells than your Dart so you will need to check.

On the front of my car I have 15x7 wheels with 4.25" of back spacing. I have 215/60 tires mounted. I was swapping from 235/60-14's on 6" wide rims to the 15x7's up front and orignally got 225/60-15 tires because they were within a couple tenths of an inch in diameter to the 235/60-14. But the wider wheels moved everthing further out and resulted on the tire hitting the leading edge of the fender when turned in. NOTE: I also have the 73+ disk brakes up front which widen the track too.

IMG_0810.jpg
 
Thank you for your hint. By the way my car is not Dart, I have the Blue 69 Barracuda fastback- in the attached pictuer.
However, I think I will go with 15x7 front, 15x8 rear - 4.25" of back spacing if it will fit like yours in the picture. although, I prefer the rear more wider so it will fill all space out the to edge of the fender; notice on your Green Barracuda, there is a bit of space between the outer edge of rear tire to edge of fender, if that space can be filled with wider wheel or wider tire, it will look nicer if I'm not mistaken! don't you think so?

69_barracuda.jpg
 
Sorry, about the car mix up the OP has the Dart.

Anyway, if I had less back spacing I could have gotten a wider tire under the car but with the 4.5" back spacing it would be to close to the spring for comfort. A friend of mine has 275/60-15's on 15x7's on the back of his 67 Cuda. It certainly fills the wheel well more but IMHO it is starting to get the cartoon car look. I am quite happy with the 255/60's.

Here is a side shot of my car. The car still has the 225/60-15's on the front in this shot.

NewTires007-1.jpg
 
i have a 73 dodge dart sport and i just bought a set of 15x8 american racing outlaw rims for it.. i am trying to find the right size tires to put on the rims.. i dont want them to rub.. my main concern is the front wheels.. please any help would be great.. i just dont want to buy 4 tires and they not work.. the dart is stock, never modified..
thanks!

16461083-346.jpg
 
i have a 73 dodge dart sport and i just bought a set of 15x8 american racing outlaw rims for it.. i am trying to find the right size tires to put on the rims.. i dont want them to rub.. please any help would be great.. i just dont want to buy 4 tires and they not work.. the dart is stock, never modified..
thanks!
 
dgc333 said:
FWIW, I have 15x8 with 4.5" back spacing and 255/60 tires on the back of my 68 Barracuda. I am about 1/2" way from the tire rubbing the spring but about 1 1/2" from the tire hitting the wheel well to the outside.

Using an 8" wide rim with 4.75" back space rim is going to put you at 1/4" away from the spring which could allow the tire to rub the spring during cornering.

If I could do it over I would prefer the 15x8 to have 4.25" of back spacing.

From your user name I am assuming you have a Dart. Dart wheel wells are not a big as Barracuda wells so you may have other clearance issues.
Click to expand...

did you put adapters on the back to use the 15x8's or no?. I have a new set of Centerlines that were just made in a 17x8 rear with 4.5 backspace and I need to install the adapters to go from the stock 5x4 pattern on my 67 cuda. Do you see any issues here or will it just be tire size that I will need to deal with?
 
No adapters. I have the large bolt circle on my car (8.25" rear axle and 73+ disks up front).
 
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