Rear tire size on a 75 Dart

[lotharamc]

Hello, is there a concencus on the size/width of tire you can put on the back of a 75 Dart? With backspacing considered. I want to confirm my measurements so I dont end up shaving the white letters off. Im going for the same size front to back so I'm not after anything huge.

Andy

 

[hotrod swinger]

245’s will work in the rear, might be a little big for the front tho.

 

[72bluNblu]

Absolute largest you can go with stock spring locations is a 255, but backspacing will have to be perfect and the car itself will need to be at the upper end of factory tolerances and the same side to side (not all of them are).

245’s are a much safer bet given factory tolerances, and should fit most Dart’s if the backspacing is correct.

Assuming we’re talking about a Dart and not a Dart Sport. The sport body’s have more room.

 

[mopowers]

Im going for the same size front to back so I'm not after anything huge.

You're going about it backwards. If you want matching sizes all the way around, figure out the biggest tire you can run in the front and use those. Generally, you're more space limited in front than in the back.

 

[H22A4]

I run 235/60/14 all around on my 75 Scamp. I don’t think I could have gone wider on the front since the inner shoulder of the tire is less than a 1/4 inch away from the front sub frame rail when the wheel is cranked over.

 

[72bluNblu]

You're going about it backwards. If you want matching sizes all the way around, figure out the biggest tire you can run in the front and use those. Generally, you're more space limited in front than in the back.

I run 235/60/14 all around on my 75 Scamp. I don’t think I could have gone wider on the front since the inner shoulder of the tire is less than a 1/4 inch away from the front sub frame rail when the wheel is cranked over.

Whoops, looks like I missed the bit about the same size tire front and rear.

But we need to know the rim diameter then. If we’re talking 15’s then you’re probably looking at 225/60/15’s, because 235/60/15’s will be too tall (not too wide) for the front. And with the backspace limits on a 15” wheel that’s all you get.

Of course if we’re talking 18’s a 275/35/18 will fit up front on an 18x9” just fine, but will be too wide in the back. I did see the part about white letters though, so I assume we’re not talking 18’s.

 

[Professor Fate]

You have to take consideration how low (or high) you have the torsion bars set, how stiff your torsion bars (rate) may or may not be, etc. But as others have said, 225 or 235 60s are the max for 15" rims in front- personally have never been comfortable with the front clearance with anything over a 225-60/15, I would get some rub when turning and compressing the front suspension with a 235 at the height I like to run my cars- like when you're turning into a parking lot and get to the curb cut...
As for 14s, I couldn't tell ya. Last time I ran 14s, it was E60-14s in front and F60-14s in the rear... that's how long it's been.

 

[MoparMike1974]

Are we talking about a dart sport or swinger? Big difference as the sport has a ton of room in the rear compared to the swinger.

 

[1971 CY Dodge Dart]

Of course if we’re talking 18’s a 275/35/18 will fit up front on an 18x9” just fine, but will be too wide in the back. I did see the part about white letters though, so I assume we’re not talking 18’s.

Yea 235/40-18’s is all I can fit in my back of my 71 Dart with an 8” wheel and 4.5” backspace.

 

[lotharamc]

Thanks for all of the reply guys. It is a 75 swinger.

Was thinking of 15x7, 4" back space, AM vector wheels. Too Dukes of Hazard y?

Im trying to hit the sweet spot with plenty of width in the back but not sticking out beyond the front fenders. I've narrowed it down to 225/60 and 235/60.

Johnny Dart, those 235s are looking good.

 

[lotharamc]

The rear leafs are a little tired. Im probably going to drop the front a bit to match. Only an inch or so.
Right now the 205/75/14s are the same dia. as the 235/60/15s. 225s are 1/2 smaller in dia.
I was more concerned with the back end when I asked. I'll do some measurements on the front this evening.

 

[H22A4]

Here’s my Scamp with 235/60/14’s. When I replace these tires I will likely go with 215/70/14 tires all round. I find the fronts stick out a little too much for my liking with 235’s. I realise that down the road (following tire change after this one in about 7ish years) I’ll likely need to upgrade to 15 inch rims since 14 inch tires will be even more scarce then.

Instead of dropping the front end to match the sagging rear end, consider replacing your rear springs with new ones. Last thing you want are the lower control arms pretty well riding on the bump stops on a full time basis.

 

[MoparMike1974]

So on my swinger I had 235/60-15 on them and they fit very comfortably. Then I swapped in an 8 3/4 with BBP and the the tire just about rubbed on the driver side. Passenger side has about 1/4" more clearance. This is not really uncommon on these cars. Also when going to BBP it sets the flange out slightly further. Just some things to keep in mind.
I ended up rolling the flare on the quarter a little but it was still too close for comfort. Threw some 225's on it and called it done.

 

[72bluNblu]

Yea 235/40-18’s is all I can fit in my back of my 71 Dart with an 8” wheel and 4.5” backspace.

Not enough backspace for BBP. I've measured out my '71 Dart and it would take 255's in the back without much issue, but with an A-body 8 3/4 and BBP axles I was looking at around 5.25" of backspace for an 8" wheel. There are several members here that run 255/60/15's on the back of their Dart's, there's enough room in the quarters if you get the backspace right.

Thanks for all of the reply guys. It is a 75 swinger.

Was thinking of 15x7, 4" back space, AM vector wheels. Too Dukes of Hazard y?

Im trying to hit the sweet spot with plenty of width in the back but not sticking out beyond the front fenders. I've narrowed it down to 225/60 and 235/60.

Johnny Dart, those 235s are looking good.

View attachment 1716111528

View attachment 1716111534

15x7's with a 4" backspace aren't going to work if you want 235's in the front. You'd be lucky to get 225/60/15's up front with only 4" of backspace. I ran 15x7's with 4.25" of backspace on my Duster and they barely cleared. 235's up front are not an easy thing to do unless you keep the ride height jacked up. There's no way they'd have worked on my Duster, although the Dart wheel opening is a bit longer.

In the back it would depend on your rear axle. Being a '75, does it have a 7.25" or 8.25" rear end in it?

 

[lotharamc]

Its the 7.25

 

[72bluNblu]

Its the 7.25

Ok, so in the back the 15x7" with a 4" backspace would be fine. The BBP 7.25/8.25 is actually narrower than the A-body 8 3/4 so you don't need all that much backspacing in the rear. But in the front a 15x7" with 4" of backspace would be pushing your luck even for a 225/60/15. To put it into perspective, the 225's on that rim would stick out 5mm further than the 275/35/18's I run on the front of my car. Doable if the ride height is high enough, but yeah, right on the edge. To be at my current ride height with the 275's I rolled my fenders.

 

[Kern Dog]

This 67 Dart of mine had Wheel Vintiques 15 x 8 Rallye wheels with almost dead center offset, 4". The rims were 8 1/2" overall width. Tires were 255-60-15s.......

They fit but it was tight. This is with a 1966-67 B body 8 3/4" axle. I swapped these into this car later.....

They fit the Duster wheelwells much better.

 

[lotharamc]

I have a fortunate situation. I know my Javelin can safely use 235/60s. Im going to try that size on the Dart and if they do prove to be too big I'll use them on the Javelin. I just ordered everything so I'll update with photos when I get it done.

 

[lotharamc]

They fit!..mostly.
The rears are fine, tight but no issues.
The fronts clear and turn with no issues. Just a heavy suspension compression while turning. Shaving the inner lip should clear that up.

To sum up, 235/60/15 on 15x7, 4" back space vector wheels.

 

[TF360]

What a cool Rim. I like American Racing wheels