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Well, I jinxed it...


Well-Known Member
Local time
2:34 PM
Dec 3, 2020
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western Maryland
So I've been talking about how much I like my Mopar Performance SS/D leaf springs in my wagon. I installed them...oh....30 (?) years ago. Car has been sitting for the last 7 years in the garage, waiting for me to get off my *** and make it run again...and I did that last weekend. New tank (harder than you'd think for a station wagon!), new carb, battery, cleaned up some wiring messes...and it runs (and still does burnouts!). On the ground again, though, the left spring is collapsed and has a flat-to-silghtly-upward arch to it.

Now, these are the "competition", 2" shorter, springs. They have the extended front mount plates that are required for use. They've been fine for years (as you can see by how long they've been in there), albeit with previously-working air shocks that are now deflated.

I looked around, and found Summit still has these springs, for 3800# rating, and am thinking about getting another set since I have the extended mounts already. But, looking at my car's sticker, it shows a rear GAWR (gross axle weight rating) of 3290. Now, I know that's gross weight (fully loaded)...but it has me wondering if the 3800# springs will be too lightweight, and fail again? Would it be worth it to get back to stock mounts and some upgraded/HD stock-style springs?

I'll likely add some helper shocks first - the air shocks were nice (I did use it as a wagon, in my pre-truck days), but I don't necessarily want to have to rely on them to support the rear end weight....
Call Springs & Things (aka ESPO) - really the only place I buy leaf springs from.
I did a standard HD + 1" setup on my '63 Savoy wagon and should have gone + 2".
Wagons have more rear weight than sedans, of course.
The SS springs generally have more arch than the HDs.
When you get them off of the car look for number stampings on the bottom, you may be able to find what you have on there now. As stated above Espo seems to be the place to get them from these days.
So here's the rear view


Passenger side



Driver side



And that's all with totally dead air shocks.
Switch to RH drive and they'll equal
out in a couple months...is a diet in
your future?
I truly hope you know I'm kidding.
If it were me....
I'd run with the 3800#'s. 250# per
spring with two in the back seat
with added station wagon payload
isn't too much to ask over 30 years
of use, though the ride may be a
little harsh until they're broke in.
LH spring sag has been a common
complaint with Jeepsters for years,
and almost all running stock
springs suffer the Jeep lean to
the driver's side. I replaced all 4
with aftermarket Ranchos. 250#'s
more capacity, and after 20 years
the Jeep sits level and rides as
smooth as a Jeep can be expected.
Spring cycles with the majority of
the weight (on the loaded side)
will always collapse to that load
over the time that load is applied.
Do you have any access to a set of scales to weigh the car? Someone in the roundy round, road race or drag sport in your area? Getting your weight is very helpful when speccing out springs and bars. Get total, front, back and corner weights. The more info you can give to who you buy from, the better.
I'm going to try and find scales.

Anyone have any thoughts about spring choice? I have been looking at a replacement set of the SS/D "race" springs (3800# rating), or possibly changing to Hemi-spec springs (with new, standard front hangars - the SS/D springs are 2" shorter and have a 2" longer front hangar). Any thoughts?

My new air shocks arrive today....we'll see how much sag I can get out of the car with those, as a starter (so I can at least drive it some, and start shaking down what I'm sure will be a comprehensive list of chassis issues...).
Most major truck stops have scales.
Cross corner weight info isn't really
necessary unless you're going to be
tracking the car. You can use a
bathroom scale for individual wheel
weights to get a rough estimate.
Most fronts (combined) will be
around 1800 lbs, most rears will be around 1500 lbs. These are general
of course.
Just did all this on my pickup for
titling purposes. 1700 lbs front,
1300 lbs rear.
Suspensions are calculated via
frequencies (htz). I'd try and stay
as close to factory as possible.
Just my .02....