Rear suspension setups

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Craig Burriss

Craig Burriss

FABO Gold Member
FABO Gold Member
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Hey guys,
I have the SS springs in the factory location on my 70 Duster with an 8 3/4. First of all, I hate how high the car sits, and I hate how the leaf springs sit in the middle of the wheel well keeping me from running wider tires.
I get crazy amounts of wheel hop on take off and because of how high the rear end sits, my pinion snubber is useless.
I’ve been looking at 3,4, and 6 link conversion kits but they’re all pretty pricey and I feel like a well tuned leaf spring setup will work just as well.
I’m thinking of going with a USCT spring relocation kit and some Hotchkis 1 inch drop springs and sway bar. That way I can fit some big ol meats out back, lower the car, and have a useful pinion snubber.
I like drag racing but there’s only a lame 1/8 track near me, and I like road racing/autoX more anyway.
So I’m thinking of setting it up to be more of a road race car than a drag car.

Anyone have any experience with the USCT relocation kit? Or some drop springs? Or just an opinion on any of this?

Thanks!
1E5037EB-C749-42F7-A46B-1AAF2FDC8349.jpeg

Almost as much ground clearance as my truck.
 
A couple of options come to mind.
Get your springs de-arched.
Flip your front spring hangers upside-down, it'll gain you a couple inches.
An adjustable pinion snubber is needed for SS springs (as well as longer shocks or shock extensions).
A spring relocation kit (as you know) is the only option to fully utilize the wheel tub.
The Hotchkiss rear sway bar won't fit with a spring relocation kit installed.
 
]The car does sit very high. There are a few ways to eliminate that; New springs, adjustable relocation kit or lowering blocks.

Pinion snubbers don't work well on the street, because if you set them up at the proper clearance they hit the body under street driving. I don't use one on the street or the strip and don't get hop. Caltracs are worth looking into. Leafs work just fine.

RMS inboard kit is tough to beat and it's adjustable

I enjoy 1.8th and 1/4 mile. They both have perks.

If you like road racing/autoX more i'[d do an inboard kit considering what you fit under the front of the car anyway.[/QUOTE]
 
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The factory SS springs are designed so that the rear of the car rises on a hard launch planting the rear tires intonthe pavement. If you are using stock length A-body springs, they are most likely reaching full extension causing your problem. Mopar Performance used to sell longer shocks which were probably repackaged C-body parts. See Fate"s comments above. That would be an inexpensive change to get you going.
But really, if you would rather have a better all around driver, SS springs are not a great choice long term.

Blue car in Statesboro, Ga? Man you gotta have them Stateboro Blues.
 
Unless you have a race car you really don't need SS springs. Contact Espo Springs and Things and tell them what you need. They can fix you up with a nice riding set of springs with the right ride height. Sell the SS springs. Some racer will need them.
 
roccodart440 said:
]The car does sit very high. There are a few ways to eliminate that; New springs, adjustable relocation kit or lowering blocks.

Pinion snubbers don't work well on the street, because if you set them up at the proper clearance they hit the body under street driving. I don't use one on the street or the strip and don't get hop. Caltracs are worth looking into. Leafs work just fine.

RMS inboard kit is tough to beat and it's adjustable

I enjoy 1.8th and 1/4 mile. They both have perks.

If you like road racing/autoX more i'[d do an inboard kit considering what you fit under the front of the car anyway.
Click to expand...
[/QUOTE]
Wow that RMS kit looks great. I didn’t know they made an inboard kit. And it’s $400 cheaper than the QA1!
 
Craig Burriss said:
Hey guys,
I have the SS springs in the factory location on my 70 Duster with an 8 3/4. First of all, I hate how high the car sits, and I hate how the leaf springs sit in the middle of the wheel well keeping me from running wider tires.
I get crazy amounts of wheel hop on take off and because of how high the rear end sits, my pinion snubber is useless.
I’ve been looking at 3,4, and 6 link conversion kits but they’re all pretty pricey and I feel like a well tuned leaf spring setup will work just as well.
I’m thinking of going with a USCT spring relocation kit and some Hotchkis 1 inch drop springs and sway bar. That way I can fit some big ol meats out back, lower the car, and have a useful pinion snubber.
I like drag racing but there’s only a lame 1/8 track near me, and I like road racing/autoX more anyway.
So I’m thinking of setting it up to be more of a road race car than a drag car.

Anyone have any experience with the USCT relocation kit? Or some drop springs? Or just an opinion on any of this?

Thanks!
View attachment 1715602680

Almost as much ground clearance as my truck.
Click to expand...
After reading all these posts , I gotta sk , which s/stock springs are you running ?
I never had that problem , dont sound right to me .
 
famous bob said:
After reading all these posts , I gotta sk , which s/stock springs are you running ?
I never had that problem , dont sound right to me .
Click to expand...

What he said .

And flip your front hangers .
I ran SS on my 73 340 Dart Sport and it sat perfect after flipping front hangers.
I did that and use sliders in the rear as well on my current Swinger.
3D7A0C4E-4BF6-44FE-BC46-B5FB86DC5C9E.jpeg
 
mbaird said:
What he said .

And flip your front hangers .
I ran SS on my 73 340 Dart Sport and it sat perfect after flipping front hangers.
I did that and use sliders in the rear as well on my current Swinger.
View attachment 1715603077
Click to expand...
I was going to flip them but didn’t want to redrill all of the holes for the mounts. And the sliders are cool too
 
Craig Burriss said:
I was going to flip them but didn’t want to redrill all of the holes for the mounts. And the sliders are cool too
Click to expand...
PLEASE don't take this the wrong way, I'm really not trying to be an ***; *BUT* I have to ask: if drilling a couple of holes to flip the hangers stops you cold, why on God's Green Earth are you looking at four links and spring relocation kits?
 
Professor Fate said:
PLEASE don't take this the wrong way, I'm really not trying to be an ***; *BUT* I have to ask: if drilling a couple of holes to flip the hangers stops you cold, why on God's Green Earth are you looking at four links and spring relocation kits?
Click to expand...
Lol, I didn’t want to drill them out just to end up still not liking them and replacing the SS springs anyway.
 
My '68 Barracuda convertible weighs 3750 without me in it. My big block '70 'Cuda weighs almost the exact same. I use two passenger side 3200 lbs SS springs on both cars with properly adjusted slapper bars, high quality shocks and Nitto Drag radials.

Both cars hook up harder than any other combination I have tried over the last 4 decades, and they ride better too. Pinion snubbers and Caltracs work great on a smooth track, but give much to harsh of a ride for me on the street.

The slapper bars work so well it shocked me, but they must be installed correctly. I bought into the bad rap they had for years, and never tried them. Until out of frustration, I thought I would give them a try. None of the off the shelf slapper bars fit correctly out of the box. I had to cut and weld mine to get them adjusted properly.

I don't like the look or ground clearance limitations resulting from lowering a car too far for practical open road use, so mine sit a bit higher than most. It does degrade the handling when doing spirited driving or road courses noticably, but not many people push their cars to the limit, which is where it is noticeable.

JohnRace2 (Large).jpg


Spring Fling (Medium).PNG


B1.jpg


slapper bar 5.jpeg


slapper bar 3.jpeg


Cuda 2.jpg
 
I used slapper bars on my 440 4 spd '70 Challenger, what night and day difference in wheel hop and spin. Like JBC426 said they need to be properly set up so they function correctly.
 
RabidScott said:
I used slapper bars on my 440 4 spd '70 Challenger, what night and day difference in wheel hop and spin. Like JBC426 said they need to be properly set up so they function correctly.
Click to expand...

One of the two wiiningest mopars in my memory , was a duster w/ slapper bars on it , of course about every other mopar racer made a joke about it ,
---till they came up against him !
He eventually got tired of winning and quit ------------
 
Craig Burriss said:
002 and 003. And yes they’re on the correct sides.
Click to expand...
Drag race springs for light weight cars around that 3K weight, correct? They were designed for the strip and a tall tire. The way things used to be done.

Lowering blocks are probably the easiest and quickest way to effectively drop the rear ride height. But I’d call up springs and things or ESPO.com

Nice wheels!
 
rumblefish360 said:
Drag race springs for light weight cars around that 3K weight, correct? They were designed for the strip and a tall tire. The way things used to be done.

Lowering blocks are probably the easiest and quickest way to effectively drop the rear ride height. But I’d call up springs and things or ESPO.com

Nice wheels!
Click to expand...

I had a set of one inch lowering blocks on my '68. They increased the leverage the rear end housing had on warping the leaf springs while under hard acceleration. The motor generated enough force to permanently bend the front passenger side spring segment into an almost "S" shape. A replacement spring and the slapper bars took car of that from happening again.

The car did corner slightly better with the blocks installed though. I ended up taking them out once the springs settled a bit.
 
jbc426 said:
I had a set of one inch lowering blocks on my '68. They increased the leverage the rear end housing had on warping the leaf springs while under hard acceleration. The motor generated enough force to permanently bend the front passenger side spring segment into an almost "S" shape. A replacement spring and the slapper bars took car of that from happening again.

The car did corner slightly better with the blocks installed though. I ended up taking them out once the springs settled a bit.
Click to expand...

I think you`ll find those springs that bent are/were made in mexico , the orig. ones back in the day didnt do that , even under a 750 h.p. hemi !!
 
famous bob said:
I think you`ll find those springs that bent are/were made in mexico , the orig. ones back in the day didnt do that , even under a 750 h.p. hemi !!
Click to expand...

I'm sure that metallurgy is tricky to get just right, so I don't doubt it. It was my '70 E-body that bent the front segment of my passenger side 3200lbs SS spring. That car has nearly 700 hp and the about the same amount of torque, 325/50-15 Nittos and a stick shift. You could feel it spring wrapping when you got on it in both cars without the slappers to stop it.
 
jbc426 said:
I'm sure that metallurgy is tricky to get just right, so I don't doubt it. It was my '70 E-body that bent the front segment of my passenger side 3200lbs SS spring. That car has nearly 700 hp and the about the same amount of torque, 325/50-15 Nittos and a stick shift. You could feel it spring wrapping when you got on it in both cars without the slappers to stop it.
Click to expand...
I used the next spring up @3600lbs. O where near that power though. I figure the weight of the car was a little bit heavier than that with me and fluids.
 
rumblefish360 said:
I used the next spring up @3600lbs. O where near that power though. I figure the weight of the car was a little bit heavier than that with me and fluids.
Click to expand...

I tried those, but found them so stiff and non-compliant on the open road. The spring was also noticeably more wrap resistant too, so probably the correct spring for a dedicated drag car in that weight range.
 
famous bob said:
I think you`ll find those springs that bent are/were made in mexico , the orig. ones back in the day didnt do that , even under a 750 h.p. hemi !!
Click to expand...
I dont own it now but , my ex hemi car still has the 002-003 springs under it , I have a bent set (drivers side), mexican springs on the shelf now ....
the good old sprigs didnt bend , just got weaker , had about 4 sets over the yrs. none bent , except this mexican set ...
 
What leaf springs did you end up going with?
 
ESPO.com is an oil trading company. I have tried several ways and never have found this leaf spring company. ????
 
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