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63/64in spring swap FAQ thread?

Stomis

Stomis

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Cant seem to find one like the 52/56 swap. I'm considering putting 63/64" springs in the back and moving my 56s up front this spring.

I also want to move my wheel base and shorten the back a little more. Thats my main question on the subject is what is the center pin offset on 63s/64s (and what the hell is it 64 or 63s btw lol). I'm curious if all that extra length comes from the back end like the 56s did over the 52s or if its split evenly.
 
Stomis said:
Cant seem to find one like the 52/56 swap. I'm considering putting 63/64" springs in the back and moving my 56s up front this spring.

I also want to move my wheel base and shorten the back a little more. Thats my main question on the subject is what is the center pin offset on 63s/64s (and what the hell is it 64 or 63s btw lol). I'm curious if all that extra length comes from the back end like the 56s did over the 52s or if its split evenly.
Click to expand...

Split evenly.
 
And if you didn't know already, they came in the new body style pickups.
I have a set waiting to be used on one of my projects, haven't decided which one yet.
I have them with the drop brakets and the longer shackles.
 
There are two different offsets for the 56's. I think the one of the Vans has the Center pin in the center of the spring from end to end. the truck models are actually offset about 4 inches.
Keith Blazer(kgblazer, here on CK5) had the van 56's on his suburban, I gave him the 56's from a truck. Basically it allows one to move his front axle 4 inches forward if one so desires.

Now I believe, that most 63's if not all, have the center pin in the center from end to end.

Also, when moving 56's up front. one must use a at least a 7.25 inch shackle on the aft end of the front springs, to make it not bind up severely.
Plus, you will need a spacer of some kind up front in the spring hanger as 56 inch springs are about 1/2 an inch narrower than the stock springs. This may be able to be made up with a wider spring bushing, IDK, for sure about that, I've always used a steel spacer supplied from DIY4X.
 
I'm wanting to do the same 56/64 swap. I'm go'in the other way though and movin the rear back 3-4" and the front forward 1-2". the search function on here is pretty hard to get anywhere with but there is a lot of info on both swaps.
 
Stock rear springs from a later model IFS truck are 64". The 63" measurement comes from people measuring eye to eye I believe. The center pin is 32" from either eye.

64's in the rear are generally pretty good, they give great flex at the sacrifice of axle wrap (fixed with a traction bar) and clearance.

56's up front generally have the same issues and benefits, other than many stock 56" spring packs come from heavier GVWR trucks. Yes, you can mix and match spring but theory and my own experience say that messing with that stuff will result in short spring life.

I run 52's on mine, on my third set, and they flex well enough but I still get axle wrap and I bash the s*** out of them all the time. There will be links in the front of mine in the near future.
 
I'm running stock 63's from like an 05 Chevy in the back, never have had any issue with wrap and do not have a traction bar in yet got the set up for one just never put it in.

I moved my rear front spring hangers forward and my rear rear hangers back and kept the axle in the same spot. Do not remember how I figured that one out, but the rear front I just swapped holes and drilled the frame and same for the back.

I have 56's in the front first set was from a van they were centered like Matt said. New set is offset have a better approach angle now.
 
I will take a pic of my 63s they do wrap.

Mine are absolutely destroyed. A traction bar is a very good addition to any leaf spring suspension.
 
Mine were basically brand new too, might have helped, the truck only had like 200 miles on it when they pulled them off.
 
well my body roll isn't all that bad but I'm running the full set up of springs I would think it would be comparable to 52's
 
I made a post a while back with lots of pictures of what I did, but it's pretty simple all-in-all. It started off being a good reference for people to work off of, and then a couple members decided they'd rather turn it in to a huge bitchfest and the thread kind of died. The pictures are still in my photobucket, so you could probably still find the thread or just look up my photobucket account. Pretty sure there's pictures in my build thread that I haven't posted in for a long time too.

64"s are on the 88- pickups, not sure if GM has ever stopped using them. My '07 Duramax has 64"s too. Every set I've ever seen is centered. I currently have 4 trucks that come with 64"s from the factory, and a K5 that I've put them on, none of my rigs have wrap problems, and I plow in AK with two of them. However, I use a spring that is designed for the weight that it has on it. I see a lot of guys pulling the overloads out (this is beyond me), or running a 1/2 ton pickup spring on a K5...A K5 has a lot more weight on the rear springs than a small pickup does. I have some 3/4 ton springs on my K5 that weren't worn out when I put them on. Even rock crawling for the past couple years, I've bent two 3/8" shackles, and the springs ride at the same height that they did originally. They will still max out the travel of my rear driveline in both directions, so it's not like the stiffer spring is hampering anything. I do have the suspension set up to prevent inverting the spring, maybe that's why they hold up well. Inverting them is a good way to fatigue a spring.

38377k5 said:
Stock rear springs from a later model IFS truck are 64". The 63" measurement comes from people measuring eye to eye I believe. The center pin is 32" from either eye.
Click to expand...

^^This
 
owenst7 said:
I made a post a while back with lots of pictures of what I did, but it's pretty simple all-in-all. It started off being a good reference for people to work off of, and then a couple members decided they'd rather turn it in to a huge bitchfest and the thread kind of died. The pictures are still in my photobucket, so you could probably still find the thread or just look up my photobucket account. Pretty sure there's pictures in my build thread that I haven't posted in for a long time too.

64"s are on the 88- pickups, not sure if GM has ever stopped using them. My '07 Duramax has 64"s too. Every set I've ever seen is centered. I currently have 4 trucks that come with 64"s from the factory, and a K5 that I've put them on, none of my rigs have wrap problems, and I plow in AK with two of them. However, I use a spring that is designed for the weight that it has on it. I see a lot of guys pulling the overloads out (this is beyond me), or running a 1/2 ton pickup spring on a K5...A K5 has a lot more weight on the rear springs than a small pickup does. I have some 3/4 ton springs on my K5 that weren't worn out when I put them on. Even rock crawling for the past couple years, I've bent two 3/8" shackles, and the springs ride at the same height that they did originally. They will still max out the travel of my rear driveline in both directions, so it's not like the stiffer spring is hampering anything. I do have the suspension set up to prevent inverting the spring, maybe that's why they hold up well. Inverting them is a good way to fatigue a spring.



^^This
Click to expand...

Good tidbit. If you can find the pictures I'd appreciate it. The pin offset was my main concern.
 
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