Spring offset and rim and tire size 68 Barracuda for thos who have done it

I'm thinking of moving my SS springs in with the 3/4 offset spring relocation kit. Don't want to mini tub. Right now I'm running BFG 255/60 15's on 8" rims with 4.25 backspace.
Input on what combination tire and rim backspace you guys who have done it to a 67-69 barracuda are running would help a bunch in my final decision.

@AJ/FormS would be the guy to talk to

But Duster rear quarters and wheel houses are about the same for clearance. With an MP 3/4" offset (it's really more like a 1/2" because the front hanger can only be offset a 1/2" before it hits the frame rail) you should be able to fit 295's in there without much in the way of cutting or trimming. 15x10's would work for you. If you're SBP still, you'd probably want about a 5.5" backspace. If you're BBP you'd want a little more, 5.75" to 6". As always, you need to measure YOUR car to see if those measurements make sense, because the bodies on all of these cars can be off as much as a 1/4" compared to another.

i have the offset parts if needed

lomchivok said:

I'm thinking of moving my SS springs in with the 3/4 offset spring relocation kit. Don't want to mini tub. Right now I'm running BFG 255/60 15's on 8" rims with 4.25 backspace.
Input on what combination tire and rim backspace you guys who have done it to a 67-69 barracuda are running would help a bunch in my final decision.

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MY 3/4 '' OFFSETS ARE 3/4''. THERE IS A SMALL AMOUNT OF TROUBLE GETTING THEM IN , IN THE FRONT. I HAD A DANA 60 WELDED UP W/ SPRING PADS WELDED UP 3/4'' CLOSER TO THE CENTER, THAN A STOCK A BODY REAR, IT DROPPED IN PERFECTLY. THERE WERE 3/4" OFFSETS MADE BACK IN THE DAY. I STRETCHED MY FRONT WHEEL OPENING TO FLUSH W/ THE INNER FENDER WELL, IN THE ORIGINAL SHAPE. AM RUNNING 295 65 15 DRAG RADIALS, ON MY 68 FORM S FASTBACK. LOOK AT MY AVATAR PIC. FINDING THE OLDER 3/4" SET UP MAY BE HARD TO DO, I LUCKED OUT. BOUGHT THEM OFF A GUY ON HERE THAT SAID THEY WOULDN`T WORK ON HIS CAR----------------------BOB

famous bob said:

MY 3/4 '' OFFSETS ARE 3/4'. O

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The hangers aren’t. None of them are. You know why? Because there’s only a 1/2” of space between the stock hanger and the frame rail. I have the MP hangers, I have the Dr. Diff hangers, the offset on the hangers is identical, and it’s a 1/2”.

So the MP shackles are offset 3/4”, and you moved the perches 3/4”. So what? You just side loaded the spring at the front hanger.

Whole thing is moot anyway. 1/2” or 3/4”, the inner wall of the wheel housing is more limiting than the springs once the offset is done, regardless of which way you do it.

t. stretched front of quarter panel to inner fender

72bluNblu said:

The hangers aren’t. None of them are. You know why? Because there’s only a 1/2” of space between the stock hanger and the frame rail. I have the MP hangers, I have the Dr. Diff hangers, the offset on the hangers is identical, and it’s a 1/2”.

So the MP shackles are offset 3/4”, and you moved the perches 3/4”. So what? You just side loaded the spring at the front hanger.

Whole thing is moot anyway. 1/2” or 3/4”, the inner wall of the wheel housing is more limiting than the springs once the offset is done, regardless of which way you do it.

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NOT NECCESARILYTRUE MINE HAD TO GO INTO THE FRAME A BIT THEY ARE WIDER THAN 1/2' Wanna bet, and come and measure them ? I MEASURED THE OFFSET BOLTS (STUDS) THEY WERTE A LITTLE OVER 5/8" =3/4" IF THE REST OF THE DEAL IS 3/4" / CLOSE ENOUGH ! I massaged the inner wheel housing from past experience, this ain`t my first rodeo ! Am running 295 65 15 drag radials on it w/ no rubbing . Blow my avatar pic up if u know how, "I don`t" !

1/2"-3/4" seems like a lot of work for so little gain. I run SS springs with 15x8's and 275x60x15 Nitto drag radials on my 68 fish.

famous bob said:

t. stretched front of quarter panel to inner fender

NOT NECCESARILYTRUE MINE HAD TO GO INTO THE FRAME A BIT THEY ARE WIDER THAN 1/2' Wanna bet, and come and measure them ? I MEASURED THE OFFSET BOLTS (STUDS) THEY WERTE A LITTLE OVER 5/8" =3/4" IF THE REST OF THE DEAL IS 3/4" / CLOSE ENOUGH ! I massaged the inner wheel housing from past experience, this ain`t my first rodeo ! Am running 295 65 15 drag radials on it w/ no rubbing . Blow my avatar pic up if u know how, "I don`t" !

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I run 15x9 with 5” backspacing and a 1/4 “ spacer. I gave all details about a year ago on a comment on my photo garage.

famous bob said:

t. stretched front of quarter panel to inner fender

NOT NECCESARILYTRUE MINE HAD TO GO INTO THE FRAME A BIT THEY ARE WIDER THAN 1/2' Wanna bet, and come and measure them ? I MEASURED THE OFFSET BOLTS (STUDS) THEY WERTE A LITTLE OVER 5/8" =3/4" IF THE REST OF THE DEAL IS 3/4" / CLOSE ENOUGH ! I massaged the inner wheel housing from past experience, this ain`t my first rodeo ! Am running 295 65 15 drag radials on it w/ no rubbing . Blow my avatar pic up if u know how, "I don`t" !

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Ok tough guy. Turn off your caps lock and settle down.

There's no magical substance the "old" MP offset hanger brackets could be made out of that would allow them to move the springs by 3/4". You know why? Because there's only a 1/2" between the standard front hanger and the frame rail.



That's a standard front spring hanger (not stock, it's a reproduction, but still a standard location hanger). That's 9/16" to the frame rail, and that's generous. So, even if the MP 3/4" hangers put the hanger right up against the frame rail, they might get you 9/16". But since they're not right up against the frame rail, you get a 1/2". The shackles are offset 3/4", the hangers are offset a 1/2". If you put the perches 3/4" in, you pull the springs on an angle, but you still don't get a full 3/4" of additional clearance at the sidewall where you need it. Not on the front. And again, it doesn't really matter, because even if you only offset the springs a 1/2" everywhere the tire will still hit the inner tubs before it hits the springs. How do I know this? Because I have the MP 3/4" offset hangers on my Duster. I measured them, realized they only move the spring a 1/2", and welded my perches at a 1/2" in. I put my rear spring sliders a 1/2" in. And before I installed my sway bar, my 295's would occasionally rub on the inner tub. Not the springs, the inner tub.

Doctor Diff says the same thing. And I'm willing to bet Cass has done this a whole lot more than you have.

DoctorDiff said:

It doesn't matter how far you offset the rear shackles or your spring perches.

Because a stock hanger mounts 1/2" away from the frame rail, you can only move the front of the spring 1/2" inward per side.

The front section of the spring is the limiting factor.

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Offset spring shackles hangers set ups

DoctorDiff said:

Installing offset hangers and shackles on an A-body aligns the outside edge of the leaf springs with the factory wheel tubs. This yields an additional 1/2" of tire clearance per side.

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relocation kit Question ??

72bluNblu said:

Ok tough guy. Turn off your caps lock and settle down.

There's no magical substance the "old" MP offset hanger brackets could be made out of that would allow them to move the springs by 3/4". You know why? Because there's only a 1/2" between the standard front hanger and the frame rail.

View attachment 1715132972

That's a standard front spring hanger (not stock, it's a reproduction, but still a standard location hanger). That's 9/16" to the frame rail, and that's generous. So, even if the MP 3/4" hangers put the hanger right up against the frame rail, they might get you 9/16". But since they're not right up against the frame rail, you get a 1/2". The shackles are offset 3/4", the hangers are offset a 1/2". If you put the perches 3/4" in, you pull the springs on an angle, but you still don't get a full 3/4" of additional clearance at the sidewall where you need it. Not on the front. And again, it doesn't really matter, because even if you only offset the springs a 1/2" everywhere the tire will still hit the inner tubs before it hits the springs. How do I know this? Because I have the MP 3/4" offset hangers on my Duster. I measured them, realized they only move the spring a 1/2", and welded my perches at a 1/2" in. I put my rear spring sliders a 1/2" in. And before I installed my sway bar, my 295's would occasionally rub on the inner tub. Not the springs, the inner tub.

Doctor Diff says the same thing. And I'm willing to bet Cass has done this a whole lot more than you have.


Offset spring shackles hangers set ups


relocation kit Question ??

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I am about done w/ this: pay no attention to the caps, I hit the dam key all the time w/o knowing it. If I recall (been a while) I had to elongate the factory hole that is in the frame for the stationary nut that's on the hangar , it would not fit, I then massaged the frame w/ a ball peen and a humongous pair of channel locks, caveing it in some , concave if u will. the bolts that are pressed in to the bracket had to be driven in w/ a hammer on top of that. I then used the cut up original front hangars for reinforcement plates, instead of buying a pair. I later had to remove one of the offset hangars to move one of the reinforcing plates to the rear, between the hangar and frame , to center the rear end exactly, 1/8" is all it took. It had to be perfect to clear the 295 65 15`s . The inner upper inner fender wells were a piece of cake, I knew where the bigger tires would try to rub , to start with, altho, I did have to massage them again later. If you ever tried to run a pair of 16 1/2" x 32" firestone W slicks on a hemi belvedere, you`d know where to massage for clearance ! I will add, that I have no idea who made the offset kit! DONE W/ THIS , DON`T BOTHER !!!

famous bob said:

I am about done w/ this: pay no attention to the caps, I hit the dam key all the time w/o knowing it. If I recall (been a while) I had to elongate the factory hole that is in the frame for the stationary nut that's on the hangar , it would not fit, I then massaged the frame w/ a ball peen and a humongous pair of channel locks, caveing it in some , concave if u will. the bolts that are pressed in to the bracket had to be driven in w/ a hammer on top of that. I then used the cut up original front hangars for reinforcement plates, instead of buying a pair. I later had to remove one of the offset hangars to move one of the reinforcing plates to the rear, between the hangar and frame , to center the rear end exactly, 1/8" is all it took. It had to be perfect to clear the 295 65 15`s . The inner upper inner fender wells were a piece of cake, I knew where the bigger tires would try to rub , to start with, altho, I did have to massage them again later. If you ever tried to run a pair of 16 1/2" x 32" firestone W slicks on a hemi belvedere, you`d know where to massage for clearance ! I will add, that I have no idea who made the offset kit! DONE W/ THIS , DON`T BOTHER !!!

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I totally believe you did all of that. I had to do exactly the same thing when I installed the MP 3/4" offset hangers on my Duster. I also run 295's on my car with the 1/2" offset. Believe it or not, we run darn near the exact same set up. So, if you would please stop telling me that if I did the stuff you did I would know, I'd appreciate it. I've been working on cars for over 25 years, I didn't start yesterday, and I have done plenty. Doesn't change the facts.

The reason the frame has to be clearanced for the MP hangers has everything to do with the lousy design of the MP hangers, and nothing to do with them moving the springs further. Mopar Performance hung a giant nut on the outside of the bracket that goes up against the frame rail, so the only way to install those hangers is to reshape the frame rail or cut a hole in it to make room for that nut. Dr. Diff's hangers have a thinner nut on the bracket, and it's set into the wall of the bracket. So, no frame rail butchery needed. But the MP hangers move the springs the exact same amount, and it's a 1/2".

You can not move the front spring hangers 3/4" inboard, because there's only a 1/2" of space there. Doesn't matter who made your brackets, there isn't enough space to offset them 3/4". You can install 3/4" offset shackles and move the perches 3/4" if you want, but at the front hanger there's only a 1/2" offset.

The picture is there, it's just that obvious.

Just crawled out from under my 68 notch. My stock location stock drivers side front spring hanger measures .698 from the frame inner wall to the bracket outer wall...the other side is .708 pretty much looks pretty close enough to 3/4 to me. I'll have it on a lift at work this Saturday, clean up the grime and take a better measurement with my planer gauge this time. 295/15's seem quite large after looking at what I have left now with stock spring location... if I could get an 11 inch patch, that would work for me...

lomchivok said:

Just crawled out from under my 68 notch. My stock location stock drivers side front spring hanger measures .698 from the frame inner wall to the bracket outer wall...the other side is .708 pretty much looks pretty close enough to 3/4 to me. I'll have it on a lift at work this Saturday, clean up the grime and take a better measurement with my planer gauge this time. 295/15's seem quite large after looking at what I have left now with stock spring location... if I could get an 11 inch patch, that would work for me...

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u can concave (neatly) the frame in a small amount w/o messing anything up, just go slow, elongate the hole for the nut just enough to barely work, u may have to use a rubber hammer to get them in too. The only thing is , they will be hard to remove. I have a 6 point cage and frame connectors , w/ front spring hangar reinforcing plates. Just because some people cant do or understand something , doesn`t mean u can`t do it . -------------25 years, he`s a puppy !