Will new XHD springs relax a bit?

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wafastr

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I installed XHD springs from Mancini in my 70 Dart and am disappointed that the car sits too high for my liking now. It is 1/2" higher on the right too. Will they relax a bit as I drive it? I don't want to buy new springs if I don't need to. So far only about 3 miles have been put on them. I can relocate the front eye bolt to the upper hole in the spring hanger to get a little lower. Combo is 360, auto, 3.55 gear, formerly a S6 car. Thanks to the collective brain trust for your input.
 
All will relax a bit, some more than others, depending on the quality of the steel used. You could take out one leaf in the middle or second down maybe.
 
You can reverse the front spring hangers by redrilling the 4 holes to lower it a little.
 
All springs settle over time. ALL. Doesn’t matter how “good” they are, over time they will sag with use.

That being said, how much they sag and how long it takes depends on the properties of the metal used and the manufacturing process. The Mopar Performance made XHD springs I put on my Challenger sagged dramatically over the course of only about 6 months, they lost close to 2” of ride height. It went from sitting considerably higher than I wanted it to actually sitting lower than I wanted it. The AFCO springs I have on my Duster have only sagged about a 1/4” in the 5 or so years they’ve been on the car. I probably wouldn’t have noticed it at all if it wasn’t for all the frequent ride height measurements based around some of the suspension work I’ve done.

The Mancini springs have a pretty good reputation, and based on what other members have said here I wouldn’t expect them to sag a lot. So if you car is sitting more than a 1/2” higher car than you want it you’ll probably have to alter the ride height with the spring eye position or lowering blocks.
 
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I have the same XHD mopar performance in my car dart sport 360. They ahve held up nicely for 5 to 6 years now. No complaints here.
 
I have the same XHD mopar performance in my car dart sport 360. They ahve held up nicely for 5 to 6 years now. No complaints here.
 
What in the world did Mancini charge you for shipping leaf springs? I just ordered aluminum rocker arms from them, and they charged me $46 for shipping. I wanted to support the smaller guys, I can’t imagine it cost $46 when I selected regular ground.
 
Are you sure you got XHD springs and not SS springs? I ask because the XHD springs are supposed to sit level. The SS springs will sit higher on the passenger side by design. If they were mine, I would double check which ones I got.
 
I have those springs on my Barracuda and they do sit high . And they are firm !
I flipped my front hangers and now the car sits better .
I have about 5k on them and they do relax a bit after a while.
 
Installed Mopar Performance XHD springs in 2014 (got them from Jegs in Columbus). They are still a bit higher than I would like and have not come down at all in 5 years, and probably 4,000+/- miles.

69 Swinger Bucyrus '14.jpg
 
These will be your friend, because those springs are not going to sag for years. I have these installed on my 70 Dart, with HD springs. Same situation you are in.

unnamed (2).jpg
 
Are you sure you got XHD springs and not SS springs? I ask because the XHD springs are supposed to sit level. The SS springs will sit higher on the passenger side by design. If they were mine, I would double check which ones I got.
This is the first thing I thought of when I read post #1.
I have 002 and 003 Super Stock springs in my Dart Sport and they were noticeably higher on the right side.
But then again, I was going for the look as well as the function of them..........
 
I wonder why mbaird disagreed with my post about flipping the spring hangers, but a few posts later he states he flipped his? LOL
 
Thanks to all for your input. My springs are XHD, not SS. I installed the 2 hole front hanger (as shown by Johnny Dart above) since I went from s6 to 360 engine, and I relocated to the upper hole. This gave me the rake I like and now I have also had the alignment done. The right side rear wheel opening does sit about 3/8" higher than the left, but it is not noticeable and may be built into the spring. Pinion angle still in spec. I'm happy. Put about 50 miles on the car so far, and though they are stiff springs I like the ride. Time to change my Avatar picture.
 
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