Few questions about runnin' 56" leafs in the rear befor purchase...

[The Pumpkinator]

Well the front end of my truck flexes far more than the rear, and rides waaaaay softer than the rear, so these HD leafs have to go.

I see that most people yank theirs off a truck in the junk yard, however I'm not very confident in running old saggy rusty leafs in the back of my truck, so I decided that I'm willing to fork over the cash for a new set. Which brings up my first question; what online company can I have mine shipped in from, and which company do you guys recommend? I've seen some advertised on JC Whitney but their spring measurements are vague

I would also like to know if the combo I want to go for will lift up the rear end of my truck higher than I want it, I wish to run these stock height 56"ers with ORD's 6" HD rear shackles. As of now, my truck has a 4" lift; TC EZ rides up front, and ORD's 4" shackle flip in the rear with stock height HD 52"s. On ORD's website they suggest running their 2.5" shackle flip with the 6" shackles on stock leafs, setting the lift in the rear at 4".

I've noticed that my shackle angle right now is around 15 degrees, so I can see that just running the extended shackles will gain me some unwanted lift, but I did some searching around here and I see that the usual angle is around 30ish degrees with the 56"ers and a pair of 6" long shackles, so the shackles will have a smaller impact on how high the rear end sits. My truck sits fairly level and I wouldn't mind another inch higher in the rear, I suppose if all else fails I can run some zero rates in the front

So will running 56" springs, 6" shackles, and a 4" shackle flip net me around 4.5-5 inches of lift in the rear? All input is welcomed

 

[Hogback Fabrication]

Contrary to what you may read, 56's are not inherently softer than 52's. The extra length means more leverage (i.e a softer feeling, flexier spring) but remember that 56's came in high GVWR 3/4 tons and 1 tons, they are usually much stiffer than 52's.

That doesn't mean that 56's are stiff, most remove leaves etc. to make them soft, though that often leads to very short spring life.

Running a 4" flip in the rear with 6" shackles will get you 5" of lift and the tail of the spring will hang way down there which is why we generally suggest the 2.5" flip and 6" shackle to get 4".

If you're looking for flex, run 64" rear spring in the rear (springs from an '88 and newer IFS Chevy, lighter GVWR will be softer). The 6" shackle really works best with those.

 

[The Pumpkinator]

If you're looking for flex, run 64" rear spring in the rear (springs from an '88 and newer IFS Chevy, lighter GVWR will be softer). The 6" shackle really works best with those.

5" of lift will do just fine! Yet with the 64s, wouldn't I need an anti wrap bar, and also move the flip closer to the rear bumper? I'm also assuming that my wheelbase will change a bit too?

I forgot to mention that I would run 4-5 leafs + the overload using the 56"ers. I figured that I would get more flex/droop from the shackles being so long and the angle being so steep with the longer springs, rather than the springs arching out more than the shorter 52s.

How far will the 6" shackles hang down from the flip with the truck sitting on flat, level ground? About 3" more than the stock shackles?

 

[Hogback Fabrication]

5" of lift will do just fine! Yet with the 64s, wouldn't I need an anti wrap bar, and also move the flip closer to the rear bumper? I'm also assuming that my wheelbase will change a bit too?

Potentially yes, but you'll be in for that with any flexy spring. Yes the flip gets moved closer to the bumper, you don't need to change the wheelbase. You can move the front mount forward on the frame.

I forgot to mention that I would run 4-5 leafs + the overload using the 56"ers. I figured that I would get more flex/droop from the shackles being so long and the angle being so steep with the longer springs, rather than the springs arching out more than the shorter 52s.

Not a huge difference between the two, especially since the 56's are still 26" on one side. You can play around with removing leaves etc and you can make them soft but be aware that they typically don't last real long when you do that.

How far will the 6" shackles hang down from the flip with the truck sitting on flat, level ground? About 3" more than the stock shackles?

With a 4" shackle flip and a 6" shackle it will be 6" lower than the stock hanger (4" lower via the flip and 2" more from the longer shackle).

 

[The Pumpkinator]

Not a huge difference between the two, especially since the 56's are still 26" on one side.

I can see 64"s getting pricey really fast, I'm almost at the point where I need to get a SYE kit and a CV drive shaft (another 2" of lift would be the death of my U joints). I can see how the 56" leafs are popular because they are mainly a bolt in process, and you wouldn't need to knock out more rivets and drill more holes, also your wheelbase stays the same since the center pin is in the same location as you've stated. Other than that, what makes them so common in others' rigs?

My blazer will still be my DD and I wouldn't mind a little body roll, my current leafs in the back are so stiff that I haven't had the need to run my sway bar within the past year, around town or 75mph on the freeway.

 

[4xcrazy]

56's also in Burbs as well...

 

[Hogback Fabrication]

I can see 64"s getting pricey really fast, I'm almost at the point where I need to get a SYE kit and a CV drive shaft (another 2" of lift would be the death of my U joints). I can see how the 56" leafs are popular because they are mainly a bolt in process, and you wouldn't need to knock out more rivets and drill more holes, also your wheelbase stays the same since the center pin is in the same location as you've stated. Other than that, what makes them so common in others' rigs?

My blazer will still be my DD and I wouldn't mind a little body roll, my current leafs in the back are so stiff that I haven't had the need to run my sway bar within the past year, around town or 75mph on the freeway.

People often feel that longer springs mean they will be softer and flexier. This isn't really true like I was trying to say before, the '88 and newer pickups use 64" springs whether they are a 1/2 ton or 1 ton crew cab dually (which are rated for WAY more weight in the bed than any of our trucks were). Those 64's sure aren't soft.

What I'm saying is that long springs aren't inherently soft and taking leaves out (or adding them) will get the results you want, but not for long. There is MUCH more to spring design than how long the leaf is and how many leaves there are (which is how practically everyone talks about springs lately). Nobody talks about the thickness or length of the individual leaves, or how they are tapered or arched. Those make a BIG difference.

Springs are designed for the job they are intended to do, when you take leaves out or put in add-a-leaves, you are asking a couple leaves to take much more load than they otherwise would and the pack sags/twists/dies much more quickly. Spring design is much more complex than just "add two more leaves for the 1 tons".

For the record, I've had 52's on the front of my truck for some time and I've been around many other trucks that messed with the longer springs. They flex well enough, I believe I'm on my 4th set now. Axle wrap control (this is up front ) has been less than good, plus I always have to worry about bending the main leaf in half while backing up when the suspension is flexed.

It's time for links and coils for me, just letting you know that switching to longer springs and removing leaves isn't the perfect solution that many people on the internet claim it to be

 

[The Pumpkinator]

I never really put in the extra thought that the metal treatment would be different on leaf packs designed for a certain GVW load . So technically I should be looking for a new set of 56" springs that have the least GVW rating (assuming that the setup I'm considering is a smart choice).

This is why I'm asking for advise based on others' experience, so I can make a smart calculated decision with the least amount of hidden costs and still be happy with my purchase.

 

[ryoken]

and just to take the "not all 56's are created equal" side... my rear leaves are 56's out of the back of an early 80's 2wd burb...

I expect these to be perfect as is in the back of my rig with the flip..... 5 leaves including the overload... so it should be immune to the issue you may have with front 52 franken packs you hear about prematurely failing...

 

[Hogback Fabrication]

For what you're wanting to do I would choose between 52's and 64's. Buying a new 56" pack will involve you removing leaves etc and it won't last long.

A lighter GVWR 52" spring pack and a shackle flip flexes well.

If you're thinking more than that look into a set of stock 64's, a 2.5" flip, 6" shackle and a zero rate to get to 5" of lift.

Again, stock 56's are going to have a really high spring rate (they only came in 3/4 and 1 tons, and some random Suburbans) so you'll have to mess with them to make them soft enough.

As far as shackle angle goes, tilting the shackle forward actually makes the ride a bit stiffer in general (depends on a bunch of variables) though it can mean more downtravel because leaves generally want more downtravel than uptravel. Of course there is a limit, there are books written on shackle angles

 

[BLIDVL]

I run the same rear spring pack Ryoken shows in the picture. 1/2 ton 1986 Suburban springs,56". They flexed too well when I removed the overload leaves so I'm going to put them back in to be better on the street.

 

[Hogback Fabrication]

Why remove the overload?

 

[BLIDVL]

I had the spring packs apart and thought I'd try them that way first,too much flex and axle wrap.

 

[The Pumpkinator]

With the way you put it, 64"s are out of the question (until my rig passes that fine line between DD and trail only), there's just to much work involved and too many variables, plus I will have to scrap my 4" flip I bought from you guys. If I buy a new set of 52"s I've defeated the purpose of having the rear end set up for droop unless I move the flip forward a bit.

I have a 6 leaf pack (that includes the overload) sitting under my truck, now the overload leaf is contoured with the radius of the other leafs, that's probably why its so d*mn stiff. The pic that Ryoken posted has a flat overload so I would suspect that those leafs would be a little softer (that is if they don't have some kind of thorough heat treatment making them more springy).

Now I'm at a loss, having the "optimum" shackle angle for articulation rides stiffer than a near vertical angle? Is this because the leaf pack compresses at a faster rate rather than the whole spring swinging with the shackle before the pack begins to compress?

I still am wondering why everyone runs them despite that they were for 3/4 and 1 ton applications as you say...

Hey Ryoken, do you see any negative affects with the 4" flip and 6" x tied shackles you plan on running with your 56"s?

 

[ryoken]

I think it should be a nice mix of performance... I was very pleased with the springs as is.. obviously i wont know till their in... the rig will see a fair amount of street time, but I think it will ramp pretty well also... my front will be more of a limiting factor there with the stock length front springs...

i wouldn't tow a f*ckton with it, but it'll drag my 1500 lb bass boat around nicely..

 

[jake 03]

I'm running stock 56s off the back of a 1/2 ton 2wd pu and they ride and flex better than the 52s that were back there. Give 56s a shot I think you will like them.

 

[The Pumpkinator]

I think it should be a nice mix of performance... I was very pleased with the springs as is.. obviously i wont know till their in... the rig will see a fair amount of street time, but I think it will ramp pretty well also... my front will be more of a limiting factor there with the stock length front springs...

i wouldn't tow a f*ckton with it, but it'll drag my 1500 lb bass boat around nicely..

I don't intend on towing anything really heavy either, these rigs are squirrely enough, but having the shackles hang down that low isn't a real concern to you? Also would the pinion angle be tipped up too far up with the extended shackles?

I'm trying to find out about all the little kinks before I make a big mistake that I would regret.

 

[The Pumpkinator]

I'm running stock 56s off the back of a 1/2 ton 2wd pu and they ride and flex better than the 52s that were back there. Give 56s a shot I think you will like them.

How many leafs are in your 1/2 ton pack? and is the overload leaf flat?

 

[76zimmer]

I don't know dick about suspensions, so I bought a set of 56" Dayton springs. I have removed maybe 3 or 4 leaves from the pack to get my ride height where I want it, I may need to add more as the weight gets piled onto the truck. I also used the 30" forward to push the rear axle back 4".
That's about all I can go and maintain adequate axle to fuel tank clearance.

 

[79bonanza]

i have kind of a related question or seeking advice rather. im running a set of 52's up front already and i was wondering what springs do you think would best match the flex of my 52 inch front springs. the 56's or the 64's