Ok im cleaning up my 56's for my rear swap and need some help. I have searched but havent found anything. Should i leave all the leafs in the pack or remove a couple. I remember someone saying they took out the 2nd and 4th leaf which looks like is a good idea. Last question, I have an ORD 4 inch flip kit will my stock shackle be too short for the 56's? Would running a 5 or 6 inch shackle be too much for the pinion angle?

all good questions, I am doing the same swap and need them answered too.

need more info.

how heavy is your truck?
wheel base?
what are you after?

i did the 56" left them stock on a swb 6000 truck and it is more than flexable enough for me. swb is over 40" of flex.

Ok got a stock blazer. Dont know the wieght on it right off hand. But it will have a full cage wont tow just needs to support wieght of people and supplies.

Springs came out of a 2wd 3/4t RC longbed truck.

I am running 4 leaf 63" rears. No overload. Stock 4 inch shackle on my sig truck. Weight: 7000lbs.

The schackle length doesn't really matter, except for the pinion angle and the ride height of the truck.

The answer also greatly depends on the specifics of the 56" spring pack you have. Huge difference in the total numbers of leaves pending whether it came off a 1/2 ton Suburban or a 1-ton dually.

How many leaves does the pack currently have?

i think it has 7. I will have to go double check.

9 leafs including the overload.

I did this swap with a buddy a while back. We put them on with all leafs at first, then after his first trip out, we ended up taking the 2nd and 4th out. But that was on an s-10. Throw them on and see how they ride.

If it has 9, I would go out on a limb and say you should be able to at least pull 2 leaves out and give it a try...likely that 7 will still be too stiff but at least a good starting point.

I am running 4 leaf 63" rears. No overload. Stock 4 inch shackle on my sig truck. Weight: 7000lbs.

The schackle length doesn't really matter, except for the pinion angle and the ride height of the truck.


How does shackle length not matter for anything else.

The longer the shackles the more distance it must travel to achieve full droop there for allowing for my droop. Yes if theres no more droop in the springs theres no point but if there is then longer shackles are a must.

I use a 6" eye to eye shackles.

For the correct shackle length to spring travel/flex, measure the eye to eye distance with no weight on the spring then again once the spring is compressed. if the differance is 4" then run a 4" shackle and it will work just fine. And remember if the spring pack is too soft you could end up with nasty axle wrap.

How does shackle length not matter for anything else.

The longer the shackles the more distance it must travel to achieve full droop there for allowing for my droop. Yes if theres no more droop in the springs theres no point but if there is then longer shackles are a must.

I use a 6" eye to eye shackles.

Well of course shackle length enables more droop. Not what I was trying to help him understand.

He asked if a stock 4 inch shackle and flip kit would be too short for the 56s. And then asked if a 5-6 inch shackle would be too much for pinion angle.

The point was I was making is that shackle length PRIMARILY affects pinion angle and ride height of the truck. Which it does.

The shackle is designed to let the leaf spring flex. To allow the spring to fulfill its purpose in life. Yes, longer can produce more droop, and theoretically, you could run 12 inch long ghetto shackles and have some CRAZY droop. Although stability in on and off road situations would be of great concern. Terribly unsafe.

This is what I am building for my rears, shackle reversal, except I'm on 6" pro comp 3/4 ton springs so my mounting points will be up higher than most others, 6" lift springs but I'm going 2" down on the lift with the new mounting mounts so 4" total lift, less lift bigger tires, 40's soon
http://i453.photobucket.com/albums/qq251/BadMonkey0608/addi110.jpg
The brackets will weld to the frame over 1/4" gusset plates, the frame is also boxed
My shackles are also 6" eye to eye seems to be the happy medium, any more they're too tall, any less and they over extend quickly

Well of course shackle length enables more droop. Not what I was trying to help him understand.

He asked if a stock 4 inch shackle and flip kit would be too short for the 56s. And then asked if a 5-6 inch shackle would be too much for pinion angle.

The point was I was making is that shackle length PRIMARILY affects pinion angle and ride height of the truck. Which it does.

The shackle is designed to let the leaf spring flex. To allow the spring to fulfill its purpose in life. Yes, longer can produce more droop, and theoretically, you could run 12 inch long ghetto shackles and have some CRAZY droop. Although stability in on and off road situations would be of great concern. Terribly unsafe.

Fair enough sir :D

I figured i'd bring this up instead of starting a new thread. I put new pads on the leafs and took two plus the overload out think it will work?

http://i6.photobucket.com/albums/y241/4wheeler4/56s.jpg

Ok i did the swap today. The two leafs i took out where too much. So i put all the leafs except the overload in. It now sits a half in taller in the back but i still have to put the tank back in so it should be level. My shocks will work for now when they max out so do the ebrake cables and brakeline SO gotta work on that. BUT here is a pic of my shackle angle think its too flat?
http://i6.photobucket.com/albums/y241/4wheeler4/shackelangle.jpg

Yeah your shackle angle is too flat you need to move the hanger back to correct it. I took the bottom 4 leaves including the overload out of my 56s and really like the ride & flex. That was on a M1028 cucv I think if you get the hanger moved so the angle is better you could do the same. I also used the stock shackle and have what most would say is not enough angle. I would call it 20* but it works well & I'm happy with it.

thats way to much angle for your shackle....it will be almost flat if not worse with a full tank of gas and supplies...u need to move the hanger back

Try taking the bottom 2 leafs + overload out of your 56's that's what I did and it has plenty of flex and with an EZ-inch is the same height as a stock 9 leaf 56" pack

edit : same page as Wagman haha

I took two leafs out of each originally and the springs went flat with the wieght with no tank. So i think what i have will work spring wise. I was just worried about the angles. I thought you just bolted the brackets in place and they were in the right spot i guess not though. What do you think move it back an inch? How about some pics for comparison?

if you bought your flip hangers swap them. (drivers on passenger/pass on driver) and that should work. Thats how ORD designed theirs.

They are i think. unless i look at them wrong they are mounted on opposite sides. WHen i put them on i made sure they would be farther back than stock. They are from ORD.

By looking at them if i flipped them the shackle would be farther forward. Could wore out springs be the cause of my problems?

I would say if the springs went flat with 2 leaves out you have some seriously wore out springs. Like I said I took out the bottom 4 and they worked great. I'm not sure why your flip bracket is so far forward it looks to me like you have the bracket on right. I would say it has something to do with going from 52 to 56s but I thought that was the reason for being able to swap them side to side. On mine the front edge of the shackle is slightly behind a straight line down from the rear edge of the bracket.

I'm not sure if an inch would be enough. When I get to the shop in the morning I'll post up some pics of mine so everyone can tell me my shackle angle is too steep:laughing: If you are trying to adjust for height you will probably gain an inch when you get the angle corrected. Then you could lose some leaves and if your shocks are not on that will make a big difference in how soft it is.

Well i want to do all this before i mount the tank back in. So i might call ORD and ask but im thinking the springs might be shot.

I can tell by your pic they are on right but you will have to move them back to get a good angle. Might as well throw the tank & some weight in the back to simulate the load and do it once.

Yeah i can throw a couple hundred pounds and see. But i wonder if the springs are shot if it is the problem or what.

When i installed them minus 2 leafs i put the vehicle weight on it and they were flat it looked ok but i figured its gonna get heavier with the cage and supplies. So i put them back in. I jumped in the back and bounced up and down and stuff and it seemed soft.

With or without shocks? Mine was crazy soft till I hooked the shocks back up. Someone else was discussing longer shackles earlier I suppose that would make the angle better but would also affect the pinion angle. if your pinion angle is good I think you have to move the hanger < which will give you more lift and allow you to pull more leaves for the same ride height. I'm running about 1" low in back but plan on redoing the fronts soon & will go with a zero rate if it's still low after that.

With some OLD rancho's. I havent checked my pinion angle yet. I will tomorow whats ideal for pinion angle i havent searched on that yet.

Just get it so the pinion & the drive shaft are pretty much in a straight line and you will be good.

Shackle angle pic as promised let the criticism begin. I'm noticing now my ORD brackets are pointing > where yours are pointing < I'm stumped now but regardless you need to move your brackets back. My pics are with the bed off and with the bed on and a 37" spare on a steel wheel in the back of the bed I'm happy with the angle and the 5 leaf (no overload) 56s.

Ok got her all buttoned up today. Let me know what you guys think. I moved the hangers a inch and a half and liked the anlge alot better.
http://i6.photobucket.com/albums/y241/4wheeler4/56shackleangle.jpg
http://i6.photobucket.com/albums/y241/4wheeler4/56flex.jpg
http://i6.photobucket.com/albums/y241/4wheeler4/56flex2.jpg

Think the springs will hold up to this?

http://i6.photobucket.com/albums/y241/4wheeler4/56springflex.jpg

The shackle angle looks good but I think you better lower your bumps or that negative arch will not do them any good.

I see you flipped the u bolts now if you cut your shock mounts loose & roll them up the axle they wont be draggin on ya and you can use your stock length shocks with your new lift.

Yeah i was looking at them and looks like i will have to extend the stops 6-8 inches.

Think the springs will hold up to this?


That's what they're for. Wouldn't be much use if they didn't flex.

I was worried it was too much negative arch. Bumpstops are on the way so im gonna adjust that anyway.

I was worried it was too much negative arch. Bumpstops are on the way so im gonna adjust that anyway.

Sorry for the sarcastic response. I wouldn't want to abuse them too often like that, but at the same time, if you have that much up-travel without rubbing anywhere, I would hate to give it up. Your flex is a combination of up-travel and droop, and limiting either, could leave a tire in the air. Sort of boils down to a durability vs. ability trade-off.

Well I can limit it A bit no prob because even with the 33's they get pushed into the body. so its not gonna be a big deal to limit up travel and when I can mess with the ebrake lines and afford new shocks I should be able to get more droop.

Well I can limit it A bit no prob because even with the 33's they get pushed into the body. so its not gonna be a big deal to limit up travel and when I can mess with the ebrake lines and afford new shocks I should be able to get more droop.

Run til you break them! replace what breaks an ride some more just my 2 cents lol