I need help with tire size

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doopdoop67

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Hi guys I bought a set of mopar rallyes 15”x6 1/2”. I want to get the Bfg radial t/a with the white letters. I’m wondering if you guys can help me out and tell me what would fit? Don’t want anything crazy wide. Something similar to a stock 69 gts car. It’s a 1967 Dodge Dart
 
lots of guys run a 225/60/15 all the way around.

With that wheel offset comes into play for tire fitment. Are you still 5x4 or have you converted to 5x4.5?
 
So if done with 73-up stuff your track has widened 3/8" per side pushing the wheels out. What is the back spacing on your rims? Typically a 15x7 with a 4.5" back spacing fits good.
 
So if done with 73-up stuff your track has widened 3/8" per side pushing the wheels out. What is the back spacing on your rims? Typically a 15x7 with a 4.5" back spacing fits good.
I’m not sure what the back spacing is. Is there a way I can measure?
 
I’m not sure what the back spacing is. Is there a way I can measure?

Just lay a straight edge across the back lip of the rim and measure down to the mounting surface.

18x9offsetspecs-jpg-jpg.jpg
 
The wheel you mention has 3 3/4" backspacing. You will be fine.
 
The wheel you mention has 3 3/4" backspacing. You will be fine.

Depends on what tires he wants to run.

With a 15x7 and a 4.25" backspace a 225/60/15 is pretty much all the way out at the fender on a BBP car, those are +6 offset rims. A 15x6.5" with 3.75" puts that tire a 1/4" further out toward the fender, that's a 0 offset rim. I wouldn't say a 225/60/15 can't work on that rim, but I know on my Duster when I was running 225/60/15's on 15x7's with 4.25" backspace I didn't have a 1/4" to the fender to spare. That 15x6.5" would put a 225 out further than the 275's I run now, and my fenders are rolled to run the ride height I'm at with those.

If that's really the backspace on those rims, I wouldn't go more than a 215 up front.
 
This is a 235-60-15 on a 6 1/2" rim. It cleared
123.JPG
130.JPG
fine. I had .920 torsion bars, a 1.25 sway bar and KYB shocks.
(Before I knew how shitty KYBs were compared to Bilsteins!)
 
Yeah but that's a Duster. His '67 Dart has a lot less room.

^^^^^^^This!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! times a billion zillion gillion.

I run a 17x7 with 4.5" BS front and 17x8 rear with ~5.25 BS. At the time of the picture below I had 73' up BBP discs in the front and BBP axle A-Body rear housing with 11" drums. I had to go custom all the way around to get what would fit my car.

GTS.png
 
This is a 235-60-15 on a 6 1/2" rim. It cleared View attachment 1715381850 View attachment 1715381851 fine. I had .920 torsion bars, a 1.25 sway bar and KYB shocks.
(Before I knew how shitty KYBs were compared to Bilsteins!)

A 235 squeezed down onto a 6.5" wide rim wouldn't be any wider than a 225 on a 7" wide rim.

Not to be contrary, but are you sure that those are 235's in those pictures? Because they really don't look tall enough to be 235/60/15's. A 235/60/15 is 26" tall, and that height by itself can cause clearance issues. Especially on a Duster. Even with 225/60/15's I barely had enough clearance to the front and rear corners of the wheel openings on my Duster. I had to max out the front lower fender brace to clear them and they were VERY close to the rear lower corner of the wheel opening on turning, and they're only 25.6" tall.

These are 225/60/15's on my Duster. Maybe it's just the pictures but the 235's in your pictures look smaller than these, not larger. The sidewalls in those pictures look shorter than these. You can also see that even with the additional backspace these wheels are pretty far out toward the fender, the top doesn't look terrible but I was running -1° camber too. At the bottom of the fender you can see the tread was outside the corners.
IMG_3619.jpg

IMG_3627.jpg


Yeah but that's a Duster. His '67 Dart has a lot less room. 215/65-15 is what I'm going to recommend.

That's not true at all in the front. In the front the Dart actually has MORE room, the wheel opening is further back so it eliminates the clearance issue to the rear corner of the opening.

In the back, yes, the Duster's have a wider wheelhouse. But that's not really an issue with anything smaller than a 245 on a Dart.

In the front can see the difference here, first one is is a Duster fender, second one is a Dart fender (for my Demon conversion). Clearance to the front corner is the same, but clearance to the rear corner is greatly improved. Width of the fenders is the same.
IMG_5296.jpg


IMG_3761.jpg
 
You may think that Dart = Duster, but people with Dusters can always squeeze wider tires on them for some unknown reason. I see it on here all the time. I'm assuming diameter is kept to 26" max., otherwise you're going to have problems with any A-body.
 
You may think that Dart = Duster, but people with Dusters can always squeeze wider tires on them for some unknown reason. I see it on here all the time. I'm assuming diameter is kept to 26" max., otherwise you're going to have problems with any A-body.

In the front it does. If anything, the Duster wheel opening is more restrictive, not less.

Why you think differently I'm not sure. I literally changed from Duster fenders to Dart fenders on the same car, with the same wheels and tires. My pictures above show the same wheels, on the same car, first with the original Duster fenders, then with '71 Dart fenders. And those are 275's, by the way. So, if there was a clearance difference between the two fenders, I know about it. Because with 275's there's no extra room anywhere.

The only tire clearance difference is in the back, the Duster/Demon/Dart Sport/Barracuda body styles have ~13" wide wheel tubs in the back. Darts/Scamps/Valiants have ~12".
 
A 235 squeezed down onto a 6.5" wide rim wouldn't be any wider than a 225 on a 7" wide rim.

Not to be contrary, but are you sure that those are 235's in those pictures? Because they really don't look tall enough to be 235/60/15's.

Shoot, now you have me doubting myself.
It was my car, I ordered the tires through Summit but now I have a fuzzy memory that the 235s were not in stock. Didn't they have a common habit of being spotty in terms of availability?
I went with the BF Goodrich because the rear tires I already had were 255-60-15s and I wanted a staggered size fr/rr.
 
I saw something a number of post back and I need to correct it. Most wheels are this backspace , unless they are custom.
15 x 7 = 4.25 backspace
15 x 6.5 = 4.25 backspace
This is a factory ralley wheel and it may apply to a steel wheel , I didn't measure those today.
This is why a 15 x 7 ralley wheel trim ring will not fit a 15 x 6.5 ralley wheel. The 1/2 inch difference
is all on the front side of the wheel. I got them off the shelf and measured them today , just to be sure.

Frank
 
A 235 squeezed down onto a 6.5" wide rim wouldn't be any wider than a 225 on a 7" wide rim.

Not to be contrary, but are you sure that those are 235's in those pictures? Because they really don't look tall enough to be 235/60/15's. A 235/60/15 is 26" tall, and that height by itself can cause clearance issues. Especially on a Duster. Even with 225/60/15's I barely had enough clearance to the front and rear corners of the wheel openings on my Duster. I had to max out the front lower fender brace to clear them and they were VERY close to the rear lower corner of the wheel opening on turning, and they're only 25.6" tall.

These are 225/60/15's on my Duster. Maybe it's just the pictures but the 235's in your pictures look smaller than these, not larger. The sidewalls in those pictures look shorter than these. You can also see that even with the additional backspace these wheels are pretty far out toward the fender, the top doesn't look terrible but I was running -1° camber too. At the bottom of the fender you can see the tread was outside the corners.
View attachment 1715381965
View attachment 1715381966



That's not true at all in the front. In the front the Dart actually has MORE room, the wheel opening is further back so it eliminates the clearance issue to the rear corner of the opening.

In the back, yes, the Duster's have a wider wheelhouse. But that's not really an issue with anything smaller than a 245 on a Dart.

In the front can see the difference here, first one is is a Duster fender, second one is a Dart fender (for my Demon conversion). Clearance to the front corner is the same, but clearance to the rear corner is greatly improved. Width of the fenders is the same.
View attachment 1715381983

View attachment 1715381982
Hey bud what's the width on the front rim on your duster with the 225 60s on them wanna do that to my 67 fish
 
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