Another 56" Spring Question

[BigCountryx]

Allright another set of questions regarding 56" spring Swap out back.

1. What year and model trucks had 56" springs?
2. With stock 56" in place of my 52" and a shackle flip (sides swapped), how much lift should I expect the 56" springs to add on top of the lift allready gained by the flip? If any at all.
3. With this same setup, what will happen to my axle location? (move back or forward) This is keeping the spring correctly installed, not backwards.

Thanks for any help. I'm trying my best to get this as right as possible on my first pass and everytime I search, I get so many conflicting reports. So I'm sorry for the repetative posts for you oldtimers.

 

[k5-newbie]

I dont think you will get any lift from the springs themselves, and if you run them the "correct" way, the axle should stay in about the same place. I did just the opposite and did lift 56's and ran them backwards.

good luck

 

[nvrenuf]

56's would be on 3/4 and 1 tons from 73-87(91), this will include 3/4 ton Subs too.

As far as lift, the 56's give no more than equivalent size 52's - stock = stock, etc.

Axle location will remain the same provided you install the 56's in their stock, forward configuration. All of the length difference is behind the pin so if you install them backwards the center pin (axle) will be moved back 4".

 

[WhiteBurb]

Some 88 - 91 1/2 ton suburbans have 56"s also. Mine does.

 

[MTMike]

This is a duplicate of the PM I sent you
-----------------------

As far as I know, the 56's did not provide any additional lift over a pair of stock 52's. What i gained by the 56's was flexibility of the added length.

The 56's are 4" longer than the 52's that were on my truck, but they're not symmetrically longer. The distance from the "front" eye to the center pin on the 56's is the same length as the 52's, and the extra length is in the rear side - so you'll find that one side of the spring is ~3-4" longer from center to eye. What I did was put the springs in "backwards" - by putting the long end in towards the front, it moved the centerpin, and thus the axle, back 3-4" from it's stock location. The reason I did this was due to the fact that I'm coming down from a 12" lift (not going from stock up like most), and because my driveline was already set up for 12" of lift, it was too long to sit at ride height w/ the 56's & flip. Turning the springs around allowed me to not have to modify my driveline.

I gained some other side effects of that though: It might be too much movement and my driveshaft may be too short. A couple positive ones were that my wheelbase was 3-4" longer, thus improving my departure angle, and allowing me to only have to trim 1 side of my rear fenders.

I did flip sides with the flip & switch kit to accomodate the longer springs, and it allowed for what I feel is near perfect shackle angle. Having them in there front-ways causes the shackle to go flat and lock up because there's just too much angle.

If you were to put them in front-ways (short side foward) your axle would sit in stock location and your extra length would just be compensated for in turning the flip kit around.

As far as which trucks 56's came out of, thats a big debate - and the only conclusion I've found is that there's no rhyme or reason. The only SURE thing is that 73-87 1-ton trucks are always 56" springs, and AFIAK all K5's are 52's. You can also find 56's in many 73-87(but not all) 3/4 tons, a few 1/2 tons, and a few suburbans. Your best bet is to take a tape measure and be sure before you buy, bearing in mind if they're not on the truck they won't be a full 56 or full 52 when they're arched up. The length is when the spring is flat or near flat.

Hope this helped

-Mike

 

[K5Chris]

mtmike & nvrenuf - helped me alot. thanks!

one more.... what length shackles would be good for the 56's & diy4x flip? 6"? is that what you got mtmike?

 

[85mudblazin]

56's are trickey. The ones out of burbs usually have more arch to them and have a different # of leaves then a pack in say 1 ton truck. I dont remeber what my springs came out of but I have 7 leafs in them and they sit almost flat at ride height. A friend of mine took out ever other leaf in his 8 leaf pack and his have more arch then mine at ride height. So you really just have to experiment with the shackle length to match your springs.

 

[MTMike]

mtmike & nvrenuf - helped me alot. thanks!

one more.... what length shackles would be good for the 56's & diy4x flip? 6"? is that what you got mtmike?

Kert at DIY4x recommended 6" shackles for 56" springs, so that's what I used and it seems to have worked great thus far. I havn't got it out on the trail and tried it yet.

 

[K5Chris]

Kert at DIY4x recommended 6" shackles for 56" springs, so that's what I used and it seems to have worked great thus far. I havn't got it out on the trail and tried it yet.

oh..... one more ?...... i know the 56" leaves wont give me any differnt lift than 52's would.... but would running the 6" shackle (w/ the 56's) give me more lift than a 4.5" shackle (w/ 52's).... or would the fact that the shackle is at a greater angle kinda cancel the extra length out?