Well, my Hpak duster's leafs have gone 'bad', and I've looked through a bunch of posts and articles, and will be going with my local spring shop when the tax refund comes back. They offer 3 profiles to works with, and I was curious what other profiles have been run, with success when swapping out the stock springs for custom builts or aftermarkets....

My other duster has a nice stiff set of V-8 springs with 5 leafs in it and I like it, but the company says they also offer a 6 leaf spring stack because they commonly get requests for that set from the drag racers with A-bodies and big blocks..... The cost increase to have the extra leaf added is $9 more than buying a 5 leaf V-8 stack....

I'm only thinking 6 because I do daily drive with a tool box and spares in the trunk and maybe my regular tools when going to a field job (of course the added weight of having a couple of bodies in the trunk doesn't help either )....


anybody willing to give their 2 cents?

-D.Idiot

How big are those tool boxes? I think the 5 leaf set would be enough without killing the ride. I like cutting the eyes off an extra main leaf and adding it to my 4 leaf, not too stiff and handles good.

I always go with the most spring capacity possible,,,because my family utilizes each vehicle to the maximum. I found my Valiant handled far better with stiffy springs....go 6!

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Yeah....Im the one who destroyed this rare, vintage automobile.....

I still have tha stock 4 leaf springs and I am suffering from axle-wrap during hard acceleration. Hopefully by the Pittsburgh race I have some super stock springs

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Leaf springs may not look complex but they do a number of different things. I will skip all the theory stuff and outline what has worked for me.

1) The front section locates the rear axle and controls wheel hop. I make the front section as stiff as possible and use clamps to limit flexing. I sometimes use 1/2 leafs to add stiffness / control to the front section of the spring.

2) The rear section handles the spring travel / load and general ride quality. The trick is to get the desired stiffness without a big arch in the spring.

3) Mopar designed the rear spring to be near flat at normal ride height. The flat spring profile allows for the correct "rear steering" effect as the spring moves off centerline. (as the spring bows, the axle moves forward)
Try to keep the spring flat as you add stiffness in order to maintain this feature. If you need to lower or rase the height, do that at the hanger, rear shackle or with blocks.
DD

My Valiant(which is a late Australian car) has 3 leafs in the rear. When I got the car it had 4, and the ride was horrible. Every bump was a bone jarring episode.
I went back to three and I can stil carry a lot of stuff in the boot without noticing it. I also now have better handling, due to there being less load transfer to the front in turns, and the obvious better traction now the springs are not binding up rear suspension travel as much. Alsd dropped the rear two inches by removing the leaf, which it needed.
I don't know about your cars over there, but our Chryslers have the spring pack biased towards the front of the spring quite considerably. Controls wrap up well enough(but not perfectly) and allows a good ride. We also have pinion snubbers on our cars too, and that helps a lot with traction, you can feel them bite when you launch hard.
Chrysler here offered lots of different spring numbers over the years, and it wasn't as logical as more springs for heavier duty vehicles. I had a sports model Valiant sedan(LeBaron) a few years ago, and it had 5 leafs on the back, and the ride and handling were great, but that car came from the factory with a lowered ride height.
Same story with my utility, had 7 leafs, but rode quite well when empty due to the fact that the bottom three leafs were not part of the pack when lightly loaded, the srping had to settle onto them for them to work.
Also, our late model cars had an elongated front spring eye in the spring, with an oval bushing. I am still trying to figure out why they did this. Any ideas?

Regards, Andrew.

I run SS springs with the front hanger flipped on the street in my swinger. They are a little rough but the traction is awesome. if I play around with some shock combos Im sure the ride would be better.

DI,

I have 5 leaf JCW springs on both cars with Energy PolyU bushings. Great stuff and inexpensive...

Possibly a bit stiff for my '64, but your Duster is heavier.

Lou

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