Max tire size - 68 dart

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BeylaMarie

BeylaMarie

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Hey guys, I'm getting ready to buy some police wheels and tires for my new 68 :)
I want to make sure they fit.. I'm new to the boards, is there a thread that talks about max tire size for different models?
I'm thinking a 225/60/15 will fit in the front, but would like to go bigger in the back and don't know what choice I have without doing a leafspring relocation.


Thanks for any help!
 
Just posted to your welcome thread. I would be weary of 265's in the rear on your Dart. Probably would be safer bet with 245 or 255 (and even that might be a stretch).
 
It would be a good idea to get under there and measure. But it seems (width wise) that 225's usually work, 245's are getting tight (I ran them on my val for several years) and some guys have gotten 255's and 265's under there with a stock suspension set up. That is going to get really tight though and lip rolling and perfect rim backspacing will be necessary.
 
There are tons of threads on max tire size for various different A-bodies and rim diameters. Make sure you look at threads regarding Dart's, because Dusters, Demon's, Dart Sport's and Barracuda's can all fit more tire out back than a Dart can.

As for tires on 15" rims on a '68 Dart- Yes, 225/60/15 will fit up front, you'll want a 15x7 with at least 4.25" of backspace to do it. In the back, with the stock spring locations, you'll probably want to keep it to a 245 at the widest. Some have managed to fit larger, but it depends on the car and how much cutting and rolling you're willing to do. As far as backspace goes, it will depend on which axle you have and what bolt pattern you're running. A-body 8 3/4's are not the same width as the 7.25" and 8.25 rear axles. And, going to big bolt pattern axles on the 8 3/4 changes the width.
 
9.75" section width will fit in the rear. Everything needs to be perfect to make this happen.
 
72bluNblu said:
As far as backspace goes, it will depend on which axle you have and what bolt pattern you're running.
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It does depend a lot on the backspace. The true answer to the "what is the biggest tire...." question is a combination of several things, but the backspacing is a HUGE factor. If you look at the tire and wheel section on FABO, almost every thread talks about backspacing. It is more expensive, but you can wheels built with custom backspacing at several places.
 
69_340_GTS said:
Maybe on a Duster (I assume you have one). They have more room to start with. Never, no way, on a Dart or Valiant.
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They WILL FIT on a Dart or Valiant all day long. Here's my car before I went to a full mini tub and relocation.

2013-05-31_18-07-02_756.jpg


2013-05-18_10-57-40_916.jpg
 
275's will most certainly fit on a 67-69 Dart with the springs offset 1/2". Albeit, the backspacing on the wheels needs to be just about perfect.

245's are about max without modification and again, backspacing would need to be spot on.

0910131204_0001.jpg
 
Funny 'cause my '69 Dart doesn't have that much room in the wheel wells, spring relocation or not. There is sheet metal in the way. Now when you start talking about mini-tubs, that is a completely different story. But the OP did not mention mini-tubs, and when I made my post earlier we were not talking about mini-tubs. You can disagree with me 100X if you want, I have measured my car and I know what will fit on it. 9.5" wide tire, maybe. Not a damn 11" tire. Maybe my car is fucked up somehow?
 
Gotta measure your own car, that is for sure. While most of them are close if your goal is to max out your tire width then the factory body tolerances are more than enough to sink you.

As for 275's, they need a 1/2" offset hanger/shackle set up. They'd fit on my '71 with the 1/2" offset. As it sits now, there's 6" from the wheel mount to the stock springs and 5" from the wheel mount to the quarter lip. Stock spring locations, stock uncut quarter lips, 8 3/4" with BBP axles. So, 11" to play with. 1/2" clearance on each side means a 10" section width would work if the backspace is dead on, most 245's are ~9.6" at the section width, but 255's are like 10.2". So 255's won't fit most cars without rolling or trimming the quarter lip, tall rear ride height etc. It has been done.

There's 12" from the inner tub to the quarter lip on my car though. Again, that's a '71 and some of the earlier cars are tighter. That's straight across as the top of the wheel opening, so that's not the whole story because the stock tubs taper at the top, but the 1/2" offset would buy enough space for 275's. Again, the backspace would have to be dead on.
 
72bluNblu said:
As for 275's, they need a 1/2" offset hanger/shackle set up.
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69_340_GTS, your car must be effed up because 275's fit all day in a stock tub on a 69 dart with offset hangers. 9.5 to 9.75 will fit on your car WITHOUT offset shackles. Add the offset shackles and the 10.5" section width fits. I've done this on a half dozen 67-69 A bodies so something doesn't add up. You can see by other peoples posts including 72bluNblu who really knows his wheels and tires that it fits their cars too.
 
275 is not "9.5 to 9.75". Closer to 11" . Maybe you don't know how wide the tires actually are?
I once had a 235/60 tire, which is 9.25", on my car and it was way too close inside and outside. More or less offset really wouldn't have helped.
 
69_340_GTS said:
275 is not "9.5 to 9.75". Closer to 11" . Maybe you don't know how wide the tires actually are?
I once had a 235/60 tire, which is 9.25", on my car and it was way too close inside and outside. More or less offset really wouldn't have helped.
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I didn't say a 275 was 9.5 to 9.65. I said a 275 is 10.5". Read my post again.


I literally posted pictures of my car with 275's on it in a stock tub with offset shackles. Those same wheels and tires are now on another FABO members car. How can you disagree with all of these members confirming they fit and direct pictures proving it?

My 275's measured out at exactly 10 7/16" sidewall to sidewall. They were on a 7 or 8" centerline wheel as shown.




 
I can tell you that 255-60-15 will fit with correct offset steel wheel .. i had stockton build me wheels ..but i need clarification .. 275-60-15 WILL "NOT " fit with stock suspension ?? thanks
 
roccodart440 said:
I didn't say a 275 was 9.5 to 9.65. I said a 275 is 10.5". Read my post again....
I literally posted pictures of my car with 275's on it in a stock tub with offset shackles. Those same wheels and tires are now on another FABO members car. How can you disagree with all of these members confirming they fit and direct pictures proving it?
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Because I have first hand experience too. And that size tire won't work on my car. No way in hell.
 
rrvolare said:
I can tell you that 255-60-15 will fit with correct offset steel wheel .. i had stockton build me wheels ..but i need clarification .. 275-60-15 WILL "NOT " fit with stock suspension ?? thanks
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That is correct. They will require offset hangers.
 
69_340_GTS said:
Because I have first hand experience too. And that size tire won't work on my car. No way in hell.
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Do you have offset hangers?

Measure your wheel tubs and take a picture. OR at least measure from the inner tub to the quarter lip and provide the measurement. I'm hard pressed to believe you have some bizzare car none of us have seen.
 
rrvolare said:
I can tell you that 255-60-15 will fit with correct offset steel wheel .. i had stockton build me wheels ..but i need clarification .. 275-60-15 WILL "NOT " fit with stock suspension ?? thanks
Click to expand...

Correct, 275's won't fit on a Dart/scamp/valiant with the stock spring locations. At least not any I've seen. Now, to confuse the issue further, 275's will fit on a Duster, Demon, Dart Sport and Barracuda with stock spring locations. But not a Dart.

As for the 255's, I know it's been done but not everyone can do it. Something important to note is that not all 255's have the same section width. Actual tire measurements for a given size vary by tire manufacturer. I've seen 255's that are listed as having a 10.3" section width and 255's that are listed as having a 10" section width. On my car the 10" section width would fit fine with no mods at all. The 10.3", on the other hand, might not. It would be super tight even if the backspace was perfect. Whether they rubbed or not would depend on the car, ride height, spring rate etc. One of those deals where everything might be fine until someone jumps in the backseat for a ride, or you hit the autoX course or whatever. And with these cars it's not unheard of for them to be different by a 1/4" on the bodywork, so then even the 10" section width would be super tight. But like I said, most cars can do it. Gotta measure.

Same point for the 275's. Depends on the tire manufacturer, car, etc. I've seen section widths on 275's range from 10.7" to 11.2", most are just under 11" which makes it a tight fit with the 1/2" offset hangers and shackles. I'm sure there are cars and tire combinations out there that would require a quarter lip trim to keep from rubbing. But you can't say you can't fit 275's on ANY Dart or Valiant even with a 1/2" offset, they will fit a lot of those cars. By the same token though, I wouldn't say they'd fit ALL Darts or Valiants either, too much variation in the bodywork and tire manufacturers to guarantee they'd fit every car.

And keep in mind too what the measured rim width is. The section width specs are measured on a certain rim. For example, 275/35/18's are usually measured on a 9.5" rim. I run mine on a 9" wide rim. So, the section width as mounted on my car will probably be a little less than the published spec. I mean, only a tenth or two, but that makes a difference.
 
69_340_GTS said:
Funny 'cause my '69 Dart doesn't have that much room in the wheel wells, spring relocation or not. There is sheet metal in the way. Now when you start talking about mini-tubs, that is a completely different story. But the OP did not mention mini-tubs, and when I made my post earlier we were not talking about mini-tubs. You can disagree with me 100X if you want, I have measured my car and I know what will fit on it. 9.5" wide tire, maybe. Not a damn 11" tire. Maybe my car is fucked up somehow?
Click to expand...

Maybe it is, because I also have 275's on my 68 with no mini tub or spring relocate. Aggresive lip trim, and some persuasion to the outer wheel house yes, & a B body axle.
Oh, and I forgot, a spacer.
Would I recommend it, or do it again? No. Not that way.
Bought the whole arrangement, Springs to lug nuts from a guy with a 69 dart going to a 4 link, tubs, & wrinkle walls.
Felt compelled to update
Mine are probably on rims that are too narrow. I measured the section width, and I have just under 10 1/4. But the fact is I drove them like that for many years, and they are on the car.
 
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I have 255/40/18's on all 4 corners and I'm currently fighting rubbing issues on all 4 corners. I did plenty of measuring and it's tight. BFH has been my friend the past month. My fronts were rubbing on the studs of my GT trim on hard cornering. My rears, with a full tank of gas, tools in the trunk, and a passenger will rub against a ledge on the outboard side (quarter panels). I have about 1/4" or less between the tire and the springs. Stick with 245's for less of a headache. I am trying to make offset shackles work at the moment.
 
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