Front Tire Size

[Bonz]

I have a 72 Dart with the GTS front suspension. I want to use my 15"x7" steel wheels with 4" backspace. What size tire can I use, comfortably. I want to use around a 26" tire.

Thanks

 

[72bluNblu]

Your best bet will be a 215/65/15. Your backspace should be 4.25" on a 15x7, like it was from the factory. Even with 15x7's and 4.25" of backspace I had very little clearance on my Duster with 225/60/15's. So little that I used them as the model for how far out I could go when I was fitting my 275/35/18's. You might be able to get away with a 225/60/15 if your ride height is stock or higher. If it's lower, you'll hit the fenders with the 225's.

 

[/72Scamp]

215/65/15. Fit my 68 valiant perfectly. Running cop wheels 15x7 4.25 bs. Fills wheel wells perfectly

 

[Bonz]

Thanks guys

 

[AJ/FormS]

Does that 15incher fit on your 72?
72s were sbp,
and there was never an oem sbp steel 15 made.
Center registers too were different.
And KH brakes require a specially shaped spider.
the 4" bs will want to get into the small BJ at full droop, or the BJ will want to tear the wheel balance weights off.So check carefully

Obviously it is possible, today, and since the early 2000s or so, to buy a specialty 15 incher to fit on the 72 hubs.

FWIW; 235/60-14s fit on 14 x 7 ET-IIs .They are 25.1 tall. I had to trim a wee bit of metal from the lowest part of the wheel openings at the front , to allow full lock cornering. I think those kidney bean slots were only 3.375 bs. I wanted as wide a track as I could get.

 

[leblanc]

205/70R15 or 215/60

 

[Nite Moves]

Ive just gone through this issue myself. Pain in the ***. Thankfully i have a friend in the tire buisness . I have 17inch rims all way around 7inch wide with a 4inch back space. I have 245's by 50 on the rear and i tried 215/50's on the frt.To wide. I just got one to try a 205/45/ and it clears the lower aspect of the fender, JUST. This is a used tire so a new one will be a touch taller. I may have to trim just a touch of the fender. Hind sight, 17 on the back looks great but i could have saved time with 15s on the frt. More tire options JMO

 

[72bluNblu]

Ive just gone through this issue myself. Pain in the ***. Thankfully i have a friend in the tire buisness . I have 17inch rims all way around 7inch wide with a 4inch back space. I have 245's by 50 on the rear and i tried 215/50's on the frt.To wide. I just got one to try a 205/45/ and it clears the lower aspect of the fender, JUST. This is a used tire so a new one will be a touch taller. I may have to trim just a touch of the fender. Hind sight, 17 on the back looks great but i could have saved time with 15s on the frt. More tire options JMO

More tire options in 15"? Uh, no. There are about 10x as many tire options for 17" rims. What is there in 15"? BFG T/A's, Cooper Cobra's, maybe a few Kumho's or generic brands with 400+ tire wear ratings depending on the width? What you should have done was get a 17x8" with 5" - 5.6" of backspace for the front. With the 8" rims 245's would have been easy even for the front, and there are about 90 different choices in a 245/45/17 on TireRack alone. Heck with a 5" backspace you could probably have run the same backspace front and rear, and just used a small spacer in the back if it got close on the springs. With an 8 3/4 rear and BBP axles you could run 17x8 with 5.25" of backspace all the way around. 245/50/17 is an odd size.

15x7 with 4.25" of backspace was the factory rim size, and is the MINIMUM amount of backspace you want to run with a 225, or even a 215 on some cars. With only 4" of backspace a 215 is max, and even then some cars might need some adjusting or trimming.

A 15" rim is limited in backspace because of the brake clearance, about the most you can run is 4.5" or maybe 4.75" depending on the style of the rim and type of brakes. With a 17" rim you can run as much as 5.6" of backspace on most rims, making a 245 or even a 255 wide front tire a piece of cake.

But for the OP with the SBP set up, it will be difficult to find much in the way of backspace options because of the 5x4" bolt pattern.

 

[autoxcuda]

I've got 245/60/15's on 15x7 4.25 backspace rims on my 68 Dart

BUT I has to move the lower fender support rod forward to push out the bottom of the front fender lip. I did this by drilling another hole forward of the one of the bottom facing lip on the front fender.

That wont really work with a car that has a front valance like a 70-72 Dart. The valance supports the bottom front fender.

 

[Bonz]

I've got 245/60/15's on 15x7 4.25 backspace rims on my 68 Dart

BUT I has to move the lower fender support rod forward to push out the bottom of the front fender lip. I did this by drilling another hole forward of the one of the bottom facing lip on the front fender.

That wont really work with a car that has a front valance like a 70-72 Dart. The valance supports the bottom front fender.

The 245/60's are what is currently mounted on my rims. You are correct, they just do not fit.

 

[Nite Moves]

I was refering to tire sizes, I havent seen anything less then a 205 in a 17inch . Im not a expert by any means. Just posting on what i have and what i went through.

 

[Marcohotrod]

I had 245/60-15 on 8.5 wheels on my 1974 dart sport, backspace was around 4.5" ? no problem

 

[autoxcuda]

The 245/60's are what is currently mounted on my rims. You are correct, they just do not fit.

you could try something like this. Maybe loosen the valence to fender bolts and mock up pushing it would with something temporary.