Leaf spring questions

[66FBCharger]

I just started looking into buying new leaf sprigs for my wife's 1973 'cuda 340. If I order 340 springs with a +1" arch, does that translate to a full inch in increased rear height? Does the spring rate having any effect on rear body height? If I put a spring that is for a 440 car (spring rate 125#) vs, the 340's spring rate of 110#, will the rear height be the same?

[303 Mopar]

If your Cuda's current springs are old, you will notice a bigger difference in height with new springs.  The 440 springs will be a little higher and stiffer with the additional leafs.  Add +1" raises the rear "approximately" an additional inch, more like 7/8".  You should also consider replacing all hardware (eye bolts, U bolts, shackles) and bushings, depending on how old.  These have a tendency to fall apart or break when you are replacing the springs. I would highly suggest calling Laura and ESPO, she is great to work with and can answer all your questions.  http://www.springsnthings.com/

[66FBCharger]

Yes the springs are old. I would replace all the hardware. I am just struggling with the standard springs or the +1". I don't want the rear of the car way up high.
Thanks for your response. I contacted ESPO for a quote and they are lower than Eaton. They responded quickly. I will probably buy from them.

[Back N Black]

I orderd springs from the dealer on Friday, $240 for the pair.

[66FBCharger]

I orderd springs from the dealer on Friday, $240 for the pair.

Back n Black,
What kind of springs did you order? $240 a pair is an awesome price.

[Back N Black]

I ordered the Mopar XHD springs. Stock for a 2 gen R/T.

[303 Mopar]

I ordered the Mopar XHD springs. Stock for a 2 gen R/T.

The XHD's are going to raise the rear end.  IMHO ESPO are the best springs out there, made in the US, and are at a great price.

[Back N Black]

Sorry, I was thinking you were looking for stock stance.

[HPP]

I just started looking into buying new leaf sprigs for my wife's 1973 'cuda 340. If I order 340 springs with a +1" arch, does that translate to a full inch in increased rear height? Does the spring rate having any effect on rear body height? If I put a spring that is for a 440 car (spring rate 125#) vs, the 340's spring rate of 110#, will the rear height be the same?

Typically, adding +1 will add an inch of ride height, but it may settle a bit above or below that.
Spring camber (arch) and rate are two seperate features of a spring and will not be identical. Camber impacts height, rate does not, so yes, a 440 and 340 spring should be at the same ride height.

I ordered the Mopar XHD springs. Stock for a 2 gen R/T.

The XHD's are going to raise the rear end.  IMHO ESPO are the best springs out there, made in the US, and are at a great price.

I wouldn't bet on the XHDs lifting the rear unless your original springs are in really, really bad shape adn have negative arch. In stock position, mopar leafs are nearly flat with minimal arch. XHD restore the original ride height of 440 and Hemi cars. But I agree Espos might be the best choice for the OP if he wants an increased ride height.