275/60/15 on rear of Duster/Dart

[QuickDart360]

Right, and you had to cut the crap out of the quarter lip. Which is not at all necessary on a Duster/Demon/Dart Sport, because there's an extra inch in the wheel tub compared to a Dart. Have both, measured both, have had 275's on the Duster and not on the Dart because they don't fit with the stock spring locations and no cutting.

On a Dart (hardtop), there's usually ~ 11" to 11 1/8" from the spring to the quarter lip if nothing is cut (depending on the car). A 275/60/15 BFG T/A has a section width of 11". So, that doesn't work. Most quarters lips are ~1", but only about 1/2" before you get into the spot welds for the quarter panel and wheel tub. On a Duster/Demon/Dart Sport, there's ~12 from spring to quarter with nothing trimmed and everything in the stock locations. That works with a 275, you can run 3/8" to the springs and 5/8" to the quarter and that should work on most cars. Some cars may need some light rolling of the quarter lip depending on body tolerances and ride height. But with the right backspace not much is required, if anything.

So a dodge dart sport with an 8.25 rear. What is a good backspace needed? I have 15x7 rally wheels now. Wheel Vintiques only offers the 15x8 in 4.50 backspace. My current 15x7 wheels are 4.25 backspace and are close in wheel well. I do have the offset mopar hangers and perches already moved.

 

[Gator]

A 275 is pretty big on a 6.5" wide wheel- you really should have them on an 8-9" rim. A 6.5 is going to pinch that tire down to the point where the tread and sidewall are going to be pretty bowed, which is going to affect wear and bead seating...
And double check that backspacing, sounds a little much to me for a stock rim. Have your springs been relocated or tubs/minitubs been installed? Where is your ride height?
I'm pretty sure you can fit a 275 into a Duster/D.S. rear wheel well but at that size you're going to have to be pretty exact with the sizing and backspacing of the wheel for your particular car- production variances are going to throw things off- what worked for someone else may not quite fit yours when things get that tight.

I have the same 275/60/15's on my 15"x7" rims for years and have not had any issues at all.

 

[496 polara]

They will fit on a 7" rim but the sidewall bulges a little and lower air pressure to keep from wearing out the middle makes it not ideal IMO.

Beautiful yellow and I love the Telestar wheels!

 

[Mopar603]

The rear end is not in the car right now, so to save a bunch of measuring, is anyone running 275/60/15 on the rear of their car. Want to make sure there is enough clearance (mostly width as the tire is around 10" wide). I am running stock, 15 X 6.5 Rallye wheels, which I think are 5.5 back space, on a 1974 Dart Sport. Thanks in advance. Ray

No sweat. Just need 15x8 with 4.25 bs. No rubbing at all.

 

[rumblefish360]

The rear end is not in the car right now, so to save a bunch of measuring, is anyone running 275/60/15 on the rear of their car. Want to make sure there is enough clearance (mostly width as the tire is around 10" wide). I am running stock, 15 X 6.5 Rallye wheels, which I think are 5.5 back space, on a 1974 Dart Sport. Thanks in advance. Ray

While I did t read the thread and I’m sure you have gotten yes answers, there are two things about larger tires I Dusters you need to know about and the first one is;

Wheel off set & back spacing. Back spacing can be generous.

But the tire itself is the issue I want to warn you about and that’s with tires that exceed 28”. The problem is not all tires listed by the metric system “275/60/15” for example or really any size but more focused on the rear tires here, are the actual diameter that the manufacturer makes them in. They are all not the same.

An example of this can be seen here n inside by side comparison at Summit Racing with their compare feature when looking at tires of the same (or any) size.

For what it’s worth, I have a set of 235/75/15’s on the back of my Duster now for simple around town or too the track driver tires. They fit inside of the wheel house and are around 30 inches in diameter. More can be put under and in the wheel housing tub. Trouble begins in width at the front of the wheel opening where the tire will contact the body first.

Here is where the in general “28 inches” of tire is called the limit and more should be carefully looked at or body work clearancing will need to be done.