Will it fit thread

[MidnightSwinger]

Car: 74 swinger, 8 1/4 rear and Super Stock springs. Stock spring location. Stock wheel tubs with super stock wheel arch cutouts.

Wheels:Weld Racing 90B-59348 Weld Racing Draglite Black Painted Wheels | Summit Racing

15x9 with 4.5” back spacing and -12.7mm offset

This would just be for the rear. With my plan to cut the fenders, will these fit? My thoughts are that they will go all the way to the fender edge and with the right tire, look really good. Will I hit the springs?

 

[GTX JOHN]

I think you will fine with anything up to L60 x 15
as those are a perfect backspacing on my Demons and
Dusters and worked OK on my Swinger 340 which has
a bit small rear 1/4s. If too close buy an offset shackle
kit from Dr. diff to get a bit more space (I think about 3/4
of an inch.

My Quarters were rolled on the lip and front of quarters rolled
back a bit but stock otherwise.

 

[MidnightSwinger]

I think you will fine with anything up to L60 x 15
as those are a perfect backspacing on my Demons and
Dusters and worked OK on my Swinger 340 which has
a bit small rear 1/4s. If too close buy an offset shackle
kit from Dr. diff to get a bit more space (I think about 3/4
of an inch.

My Quarters were rolled on the lip and front of quarters rolled
back a bit but stock otherwise.

I’ve got no issues with rolling or cutting the fenders, but I’m hoping to stay with stock spring location.

Your demon is exactly what I picture, nice stuffed tire look.

 

[72bluNblu]

The 8.25 is narrower than an A-body 8 3/4, even if the 8 3/4 hasn’t been upgraded to BBP axles.

4.5” backspace with a 15” rim and tires with a tall sidewall is going to be pretty close on the springs. I test fit a set of 17x9’s with 275/40/17’s on my Duster when it had the stock spring locations and a BBP 7.25, which is the same width as the 8.25. I used a spacer to put them at a backspace of 4.75”, they cleared but were very close to the springs.

So the 4.5” backspace will likely clear, but with the larger sidewall bulge you’re going to have with the 15” rim/tire combo it will still be very close. A thin spacer might be necessary, depending on what tires you put on those 15x9’s. On the bright side, with SS springs and that backspace you probably wouldn’t need to do much of anything to the quarters to clear a 275.

 

[MidnightSwinger]

The 8.25 is narrower than an A-body 8 3/4, even if the 8 3/4 hasn’t been upgraded to BBP axles.

4.5” backspace with a 15” rim and tires with a tall sidewall is going to be pretty close on the springs. I test fit a set of 17x9’s with 275/40/17’s on my Duster when it had the stock spring locations and a BBP 7.25, which is the same width as the 8.25. I used a spacer to put them at a backspace of 4.75”, they cleared but were very close to the springs.

So the 4.5” backspace will likely clear, but with the larger sidewall bulge you’re going to have with the 15” rim/tire combo it will still be very close. A thin spacer might be necessary, depending on what tires you put on those 15x9’s. On the bright side, with SS springs and that backspace you probably wouldn’t need to do much of anything to the quarters to clear a 275.

I was hoping you would respond. I have a set of 235/60 M/T drag radials for now to use as rollers. When I buy tires I would like to go minimum 275/60 probably in the same M/T drag radial.

Sounds like I might be able to bolt the weld/235 combo on for now. I’ll look into the offset spring mod before I go any wider.

 

[RustyRatRod]

Although this isn't exactly applicable to your 74, I had a 65 Valiant I had a stock width 8 3/4 under. I put Centerline 15 x 9.5" Auto drags on the rear. I got them on there by using the MP "3/4" spring relocation kit.....it actually moves the springs in a hair over 1/2" as that's about all the room there is. BUT, that gave me way more room than I imagined. I ran a 28 x 9 x 15 MT ET Street and had room for bigger. I did however roll the inner lip of the outer wheelhouse up just in case. Of course, to use that kit or one similar, you have to relocate the spring perches. Really not a difficult job and does give some extra room. Just food for thought.

 

[MidnightSwinger]

@72bluNblu If I may ask your opinion, what if I am trying to accomplish this look eventually? Would I be better off buying wheels with less backspacing? This is purely aesthetic as I don’t plan to race the car. I want the stuffed rear tire look without spring relocating if possible and without sticking out so far it looks cartoonish.

 

[GTX JOHN]

I’ve got no issues with rolling or cutting the fenders, but I’m hoping to stay with stock spring location.

Your demon is exactly what I picture, nice stuffed tire look.

The offset shackle kit is an easy deal. Hardest part is
rewelding spring pads which is simple for any welder.
Just do not get housing smoking hot (use wet rags) or it
may warp.

Next option: Calvert Racing makes a narrow one piece spring
that would increase clearance on tires. I used it on my duster year ago
for a few weeks even at the race track without adding his bars and
it worked great. It is a 10 Second small block race car (Hot Rod Project Car)
John asked me not to tell anyone how well the springs worked without his traction bars.

 

[GTX JOHN]

The 8.25 is narrower than an A-body 8 3/4, even if the 8 3/4 hasn’t been upgraded to BBP axles.

4.5” backspace with a 15” rim and tires with a tall sidewall is going to be pretty close on the springs. I test fit a set of 17x9’s with 275/40/17’s on my Duster when it had the stock spring locations and a BBP 7.25, which is the same width as the 8.25. I used a spacer to put them at a backspace of 4.75”, they cleared but were very close to the springs.

So the 4.5” backspace will likely clear, but with the larger sidewall bulge you’re going to have with the 15” rim/tire combo it will still be very close. A thin spacer might be necessary, depending on what tires you put on those 15x9’s. On the bright side, with SS springs and that backspace you probably wouldn’t need to do much of anything to the quarters to clear a 275.

Well, I never was aware of the 8 1/4 being narrower than the 8 3/4 in A bodys.
I thought that they were both around 56 1/2 drum to drum.
However, I am a strictly a Drag Racer and not a restorer.
Appreciate the information!
How much narrower is it?

 

[GTX JOHN]

I have run a Billet Wheel spacer (NOT Chinese cast junk) with longer
wheel studs and longer lug nuts that go thru the entire wheel and most of
the spacer. This would hedge the problem and I have done that even on my
800 HP+ Scamp (Got to finals in Pinks All Out) which is similar in 1/4s to you Swinger
and we really beat on it (The drivetrain not the fenderwells).

 

[RustyRatRod]

Well, I never was aware of the 8 1/4 being narrower than the 8 3/4 in A bodys.
I thought that they were both around 56 1/2 drum to drum.
However, I am a strictly a Drag Racer and not a restorer.
Appreciate the information!
How much narrower is it?

I don't know how much narrower it is, but I do know from experience that ALL THREE rear axles that were put under A bodies.....the 7 1/4, 8 1/4 and 8 3/4 are all three different lengths. I never wouldda believed it, but they sire are. Ain't that a kick in the head?

 

[TF360]

Your safest bet is measure for yourself. Just google how to measure wheel backspace. It's easy and you will have the correct measurement

 

[MidnightSwinger]

Your safest bet is measure for yourself. Just google how to measure wheel backspace. It's easy and you will have the correct measurement

I don’t have the 8 1/4 installed yet and an insane deal came up on those wheels, otherwise I agree 100%.

 

[33IMP]

I don’t have the 8 1/4 installed yet and an insane deal came up on those wheels, otherwise I agree 100%.

Too much backspace is FAR more desirable than too little. (Except in your case, cause you don't have a problem cutting the fender, lol)
With too much backspace, you have the option of using a spacer to put the tire Exactly where you want it. With too little b.s, you don't have that option.
I have run 9 second quarters with rear spacers, but they are quality billet spacers I made myself. If you're gonna run spacers get the best you can get, not the cast multi bolt pattern crap.

 

[72bluNblu]

@72bluNblu If I may ask your opinion, what if I am trying to accomplish this look eventually? Would I be better off buying wheels with less backspacing? This is purely aesthetic as I don’t plan to race the car. I want the stuffed rear tire look without spring relocating if possible and without sticking out so far it looks cartoonish.

View attachment 1716001020

View attachment 1716001021

If the plan is an 8.25" rear I would stay with the 4.5" backspace. With the large tires you may need a small spacer, but I think you'll be close enough that the spacer would be less than a 1/4" anyway. That car has highly modified quarter openings, like super stock style. And there's a ton of rubber outside the quarter. If you're planning on cutting the quarters out it will work, otherwise you'll need to go substantially narrower than that.

Going with less backspace doesn't really help you, at least not once you get past about 3/8" of clearance to the springs.

Well, I never was aware of the 8 1/4 being narrower than the 8 3/4 in A bodys.
I thought that they were both around 56 1/2 drum to drum.
However, I am a strictly a Drag Racer and not a restorer.
Appreciate the information!
How much narrower is it?

So the measurements for the A-body rear ends, wheel mounting surface to wheel mounting surface (WMS), are like this

SBP 8 3/4 - 57 1/8”

8 3/4 w/ BBP axles - 57 13/16”

BBP 8.25/7.25= 56 3/4”

And I believe the SBP 7.25's are a little different as well, I don't have that measurement.

There's a list of all the 8 3/4 widths here on the forum. I posted it, although a lot of it was borrowed from the list over on MoParts. I added the 7.25/8.25 measurements, as well as the BBP A-body 8 3/4 measurements. And I've confirmed quite a few of the B body axles widths for different years, as well as a couple of the truck and C-body measurements too.

An accurate 8 3/4" rear axle width list

 

[MidnightSwinger]

If the plan is an 8.25" rear I would stay with the 4.5" backspace. With the large tires you may need a small spacer, but I think you'll be close enough that the spacer would be less than a 1/4" anyway. That car has highly modified quarter openings, like super stock style. And there's a ton of rubber outside the quarter. If you're planning on cutting the quarters out it will work, otherwise you'll need to go substantially narrower than that.

Going with less backspace doesn't really help you, at least not once you get past about 3/8" of clearance to the springs.

That’s the plan, I already have the template. My thought on less back spacing is that more of the wheel will
be in the 1/4 to accomplish that look.

 

[72bluNblu]

That’s the plan, I already have the template. My thought on less back spacing is that more of the wheel will
be in the 1/4 to accomplish that look.

Yup, that's how it works. The less backspace the more the wheel will stick out. But if you overdo it you'll either end up with a lot more rubber outside the quarter, or a skinnier tire. I think 4.5" is the most you'll want to run, I'd say the least is probably around 4". More than that and you're not benefitting from the clearance to the spring.

 

[MidnightSwinger]

Yup, that's how it works. The less backspace the more the wheel will stick out. But if you overdo it you'll either end up with a lot more rubber outside the quarter, or a skinnier tire. I think 4.5" is the most you'll want to run, I'd say the least is probably around 4". More than that and you're not benefitting from the clearance to the spring.

That’s what I am looking for, thank you. Your wealth of knowledge on this subject is invaluable, I appreciate your input.

 

[RustyRatRod]

If the plan is an 8.25" rear I would stay with the 4.5" backspace. With the large tires you may need a small spacer, but I think you'll be close enough that the spacer would be less than a 1/4" anyway. That car has highly modified quarter openings, like super stock style. And there's a ton of rubber outside the quarter. If you're planning on cutting the quarters out it will work, otherwise you'll need to go substantially narrower than that.

Going with less backspace doesn't really help you, at least not once you get past about 3/8" of clearance to the springs.



So the measurements for the A-body rear ends, wheel mounting surface to wheel mounting surface (WMS), are like this

SBP 8 3/4 - 57 1/8”

8 3/4 w/ BBP axles - 57 13/16”

BBP 8.25/7.25= 56 3/4”

And I believe the SBP 7.25's are a little different as well, I don't have that measurement.

There's a list of all the 8 3/4 widths here on the forum. I posted it, although a lot of it was borrowed from the list over on MoParts. I added the 7.25/8.25 measurements, as well as the BBP A-body 8 3/4 measurements. And I've confirmed quite a few of the B body axles widths for different years, as well as a couple of the truck and C-body measurements too.

An accurate 8 3/4" rear axle width list

They are......and let's not forget, there's ONE MORE. The Dana under the Hemi cars. <rolls eyes> LOL

 

[MOPARMAGA]

@72bluNblu If I may ask your opinion, what if I am trying to accomplish this look eventually? Would I be better off buying wheels with less backspacing? This is purely aesthetic as I don’t plan to race the car. I want the stuffed rear tire look without spring relocating if possible and without sticking out so far it looks cartoonish.

View attachment 1716001020

View attachment 1716001021

Remember now those 68s only look that badass because of the wheel well cut outs, now you might as well mini tub it and buy my narrowed 8.75 housing from me. It's 47 inch flange to flange