Rear leaf springs

Author Topic: Rear leaf springs  (Read 12910 times)

Offline Purple73Cuda

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Rear leaf springs
« on: July 31, 2009 - 12:22:29 PM »
My car is a '73 Cuda340. Are the leaf springs different than a 'Cuda with a 318? With a stock spring, do the cars sit level or low in the back? Who makes a good replacement spring? Are the XHD springs that Mopar sells overkill for this car? ( I don't want to end up with a rough/stiff ride. Most of the time I have the 3 kids in the back seat.)
I have air shocks now, that I want to pitch out. I want to go to 255/60R15 tires in the rear and I don't want to have a problem with the tires hitting. We like to have a little rake to the car. I would like to accomplish this without air shocks.
John
'73 Cuda 340
'70 RR 440+6
'66 Charger 383




Offline 72bluNblu

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Re: Rear leaf springs
« Reply #1 on: July 31, 2009 - 12:37:36 PM »
I believe that the 340's and 318 cars used the same rear springs, but I could be wrong. I have XHD's on my car, the ride is just fine. Definitely stiffer than stock, but not at all bad. Although I will say that if you're looking for a raked look by having the rear end in the air (vs the front end in the weeds), then the XHD's may not be for you. They're a pretty flat spring, and they sag quite a bit after initial installation. Mine sits pretty much exactly where it did with the stock 40 year old 318 springs in the back.

Summit is selling stock replacement springs for the e-body's now, although I'm not sure of their specs. I'm just guessing, but they're probably in the same ballpark rate-wise as the XHD's (around 140 lbs), but how they hold up height wise is anyone's guess.

You might try getting a set of EXPO's, or looking on e-bay. There's seller on eBay that has 6 leaf springs for a 2 inch "lift" that are supposedly american made. Not really sure what the spring rate is like though, you could try contacting him. I thought someone on here was talking about buying a set...

http://cgi.ebay.com/ebaymotors/REAR-LEAF-SPRINGS-70-73-CUDA-CHALLENGER-2-LIFT_W0QQitemZ350125278192QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item518517c3f0&_trksid=p4506.m20.l1116

Offline matt63

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Re: Rear leaf springs
« Reply #2 on: July 31, 2009 - 12:50:45 PM »
I bought springs from ESPO http://www.espo.com/  They were good to deal with, had reasonable prices and you can order custom springs i.e. stock +1"

Matt in Edmonton

'68 Valiant
'73 Cuda 340 4 speed (408) SOLD

Offline Purple73Cuda

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Re: Rear leaf springs
« Reply #3 on: July 31, 2009 - 12:54:42 PM »
Can anyone tell me what the stock height is? I can let the air out of the air shocks and measure from the ground to the wheel well lip. If the springs are sagged and I order +1" I could end up with more than 1".
Thanks Matt. How are ESPO's prices?
John
'73 Cuda 340
'70 RR 440+6
'66 Charger 383

Offline HP2

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Re: Rear leaf springs
« Reply #4 on: July 31, 2009 - 03:19:38 PM »
Mopar never specified a rear ride height. It always was just what it was. The front ride height specified by the service manual, however, will put an E body with a nose high rake.

Typically, installed at rest, the stock leafs should have 1.5-2" of arch to them for the lightweight, 4 leaf springs and around 2-2.5 worth of arch with the XHD spring packs.

Personally, I think XHD springs are a a good compromise for street and light duty track use. Not too harsh or too soft.

Offline MEK-Dangerfield

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Re: Rear leaf springs
« Reply #5 on: July 31, 2009 - 06:43:00 PM »
Small blocks had 5 leafs...Dare I say leaves?   :lol:

Big blocks had 6 leafs. I went with Espo(Springs N things) because the stock height wasn't enough for me. They offer 1", and 2" over stock height. I think you probably want 1" over, but I went with 2" on my big block because my trunk has a very heavy tool box and many spare parts that I travel with.   :o

  Mike

Mike

1970 Challenger - SOLD
2016 SXT+.  1 of 524 SXT+'s in Plumb-crazy for 2016.

Offline 71Plym

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Re: Rear leaf springs
« Reply #6 on: August 01, 2009 - 06:52:53 PM »
ESPO 1" over on my Cuda.


wagesofsin

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Re: Rear leaf springs
« Reply #7 on: August 01, 2009 - 06:55:58 PM »
ESPO 1" over on my Cuda.





sweet car !!

Offline Purple73Cuda

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Re: Rear leaf springs
« Reply #8 on: August 03, 2009 - 07:23:14 AM »
Mike (MEK)
Those rear tires on your car are 255/60x15s on 8" rims?
John
'73 Cuda 340
'70 RR 440+6
'66 Charger 383

Offline MEK-Dangerfield

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Re: Rear leaf springs
« Reply #9 on: August 03, 2009 - 11:06:24 AM »
Mike (MEK)
Those rear tires on your car are 255/60x15s on 8" rims?

No, they are 7" rims.

Mike

1970 Challenger - SOLD
2016 SXT+.  1 of 524 SXT+'s in Plumb-crazy for 2016.

Offline bentpshrods

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Re: Rear leaf springs
« Reply #10 on: August 03, 2009 - 10:21:28 PM »
   I also went with the Espo 1" over springs also. Went with the polygraphite bushings  but when the springs arrived it had the rubber bushings instead. Called Espo and they had the correct bushing to me in three days.

Offline FM3V6M

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Re: Rear leaf springs
« Reply #11 on: August 04, 2009 - 12:09:45 AM »
I went the other way and lowered mine 1" with the XV Motorsports level 1 setup.

Offline tomsa

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Re: Rear leaf springs
« Reply #12 on: August 04, 2009 - 07:11:45 AM »
Summit is selling stock replacement springs for the e-body's now, although I'm not sure of their specs. I'm just guessing, but they're probably in the same ballpark rate-wise as the XHD's (around 140 lbs), but how they hold up height wise is anyone's guess.


But isn´t the part number P4452984 a mopar performence xhd spring?

Offline Purple73Cuda

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Re: Rear leaf springs
« Reply #13 on: August 04, 2009 - 08:58:18 AM »
bentpshrods,
That looks like how I want my 'Cuda to sit. What size tires and wheels are on the car?
FM3V6M,
Beautiful car!
John
'73 Cuda 340
'70 RR 440+6
'66 Charger 383

Offline HP2

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Re: Rear leaf springs
« Reply #14 on: August 04, 2009 - 02:08:31 PM »
But isn´t the part number P4452984 a mopar performence xhd spring?


Yes, but Summit also offers SUM-7074CH  which is their house brand stock height spring (which they claim is correct for your car's OEM engine and weight rating. It is a 5 leaf spring) as well as SUM-7074CH-2 which is a 2 inch drop spring, also 5 leaf. Since most stock mopar springs have very little arch in them by design, these may be down around 1-1.5 worth of arch in the installed position.

If you want to go even lower, Mopar offers their zero arch oval track springs, P4452414. These are a four leaf design, but the leaves are 9/16 thick instead of 7/16 like stock, and they have a 1.5" shorter front segment like a super stock spring.

If you want the drag racing look like bentpshrods and 71Ply then you would want to get Espo's +1 set up.