Chevy 63 Swap

Trail Toys is available to help with your swap if you're local, or just want to bring your rig down to Texas. Send me an email to discuss your build. nathan@trailtoys.net

Here's the rundown of my chevy 63 leaf spring swap. I figure it'll be nice to have this as it's own dedicated thread for ease of searching.

I decided to go with the Chevy 63 leafs primarily to hold up the heavy flat bed.

Taco leafs that will support the weight of the bed, toolbox, and gear don't exist. The allpro expos state an extra 400 to 500lbs of cargo. Here's the breakdown of the weight that's currently out back.

Toolbox = 200lbs (without tools or gear)
Bed = approximately 350lbs (I should get an actual weight on it)
Stock DCSB bed = 250lbs

So I'm 300lbs over stock in the rear. The expos will only give me 100-150lbs of capacity before I start sagging. I don't think that will work. The expos also cost $500.

So, in enters the chevy 63" swap idea. When I weighed my truck, the back end weighed in at 2900lbs. This was on a cat certified scale.

Here are the box weights for the 1/2 ton Chevy pickup.

Box curb weights:

Standard box - 2219lbs
Long box - 2267lbs

Payload capacity:

Standard box - 1508lbs
Long box - 1802lbs

Let's look at the standard box. I'm 681lbs heavier than the stock curb weight so I'll have to reduce the payload capacity by that much. That would leave me with 827lbs of payload capacity if I just run the stock springs. I could also choose to add an add a leaf to the chevy springs.

Cost breakdown:

Ruffstuff ideal 63" swap kit = $226.50
63" springs from the junk yard = $100 (supposedly)
Add a leaf for 63" springs = $80 (if I need them)

Total cost = $406.50

Right off the bat I decided to use Skyjacker 5" lift springs instead of factory chevy 63's. The leafs I used from Skyjacker are CR55's. If I had to do it again I would buy the CR75's, which are meant for the 3/4 ton truck. The 5" lift spring is significantly longer than the stock 63's, which have resulted in more droop.





When ordering the ruffstuff swap kit you'll need to know the axle diameter so they send you the correct u-bolts. The 8.4" sport rear axle tubes measure out to 3.25". Here's what you get in the Ruffstuff kit. The only thing you'll be missing is a rear perch for the rear shackle hanger.



Time to start putting the kit together. You have to weld up the front spring hangers from ruffstuff.







Powdercoated shackles



Things never go according to plan. I had to buy an air chissel to get the old OME bolts out of the lower shock mounts.



I had cut the rivets for the rear spring hangers when I built my flatbed, so taking them off now was the easy part.



The skyjacker leafs have two different size eyes. The front requires a 5/8" bolt and the rear needs a 1/2" bolt. I have no idea why they're different, but keep it in mind if you're going to use these leafs.



Front spring hangers gone.



Tacked in the front spring hangers and called it a day.



Rear spring hangers. Due to our frames tapering at the rear you'll need to build a perch for the rear hanger. This was my solution.





With everything tacked in place I tried out two of the four leafs and found that they were no where near the capacity I needed. Time to put the whole pack back together and see how they work.



All four leafs turned out to be too much. In the end I went back to four leafs, but that was after I had moved the rear hanger forward.



You can see that my shackle angle is too steep here. I didn't know enough at the time and welded everything out. I had to cut off the hanger and turn it around, which moved the hanger about 1.5" forward.



Fool droop with the wrong shackle angle and no retainers on the leafs.





Paint









So one of the problems I ran into was the axle rotating enough that the stock shock locations wouldn't line up. I had to take the axle shim out to get the shock to fit. The skyjackers are way to bouncy to run without a shock for more than a few feet.

Doing a little testing before buttoning it up to go home.



Phill stopped by the shop this evening to help me measure for the new shocks. I took measurements between the underside of the bed and the centerline of the shackle. Here's what I got.

Compressed = 29.5"
Extended = 43.75"
Distance between flat leaf and bump pad = 6"
Brake lines = 36" (there will be plenty of slack with that length)

So with adding an inch for forced travel I'm looking at 15.25" of travel in the rear.

I decided to run 18" shocks vertical so that I can dampen the heavy rear bed and so that I won't have to strap the axle.



The 18" shock has a compressed length of 28" and an extended length of 46". That would give me 1.5" of exposed shaft on compression and an extra 2.25" of extension past my calculated numbers. Definitely provides more room for error on my part. The additional cost to go from the 16" to 18" shock is only $25, so it's kind of a no brainer.

Bump stops

I did not take into consideration how much these bumps would compress, so in this picture they're 2" too short.



New shocks



I also ordered new brake lines at 10" over stock. So far I haven't had any issues with them.

Rear shock mounting:

I used a Ruffstuff lower shock mount. We had a few issues with the mount though. It should have been a little longer on the sides to allow the supplied bolt to fit. You can see here that it hits the frame.

I also did a little machining since I didn't have spacers on hand. I turned down, and bored, a piece of sch 160 1/2" pipe for bushings. Each one is 1/4" thick. That also helped with spacing out the tabs since the shock eyes are 1-1/4" wide.



The point of no return. No more stock shock mounts.







Tacked on the upper shock mounts to the flatbed. Quickly realized they needed to be angled to get the lower shock mount to line up.



First shock mocked up.







With 4.1" backspacing on the wheels and a 1.25" spacer it looks like there will be plenty of room for the shocks.



All welded up.





I added 2" to my bumpstops to keep the leafs from going negative and the shocks from bottoming out. Everything looks good to go. I clear the tires at full flex, but I may move up to a 1.5" wheel spacer to gain a little wiggle room.













And finally some real world testing. I still need to build a traction bar, but that will have to wait for another day.

 

Holy cow I need a cold shower

 

I am doing the 63 swap soon. I have all of the parts ready, including 16" kings. I don't have a flat deck (yet), so I'm building a bed cage to go through the bed with the shocks.

My question is, what orientation should the shock eyes be? I have axle shock mounts that would put the eye in the same orientation as stock. Should I change them to be like yours? Or can I just turn the upper mounts 90°? Or are they fine both facing the same way?

Thanks so much for your time @SMKYTXN ! I know this is pretty old and your truck is very different now, but I think you still have the same rear setup. Anything you would do different?

 

Goddamn that rear flex!!

 

Even with the SAS I'm still on my 63's. I will eventually link the rear, but she's holding up just fine as is.

I like both the top and bottom bolts to be perpindicular to the axle. That way you don't have any bind.

 

I don’t know the answer to this but wouldn’t you want one parallel to the axle and one perpendicular to avoid binding? That would allow the shock to articulate front to back and side to side if the axle were to shift in either direction during travel? Or is it assumed that on leaf springs the axle doesn’t shift forward or backward during flex?

 

Your axle will move a bit front to back with the travel of the leafs, but not enough to overcome the travel of the joint in the shock. The axle moves a whole lot more in line with itself, vertical travel of one wheel. Having the bolt perpindicular to the axle allows it to roll on the bolt.

I'll correct my previous post where I said parallel. I've done both though, both perpendicular, and opposing. It's best to tack everything in and verify it's not going to bind though.

 

So I’m setting up some 63s on my truck. They’re just springs pulled from the junkyard. Is there a final consensus on shackle angle when you’re setting these up? From what I read it’s 45 degrees during setup and 20 at ride height when on all 4 wheels. Is that right? I’m seeing different things in multiple places.

 

Was your truck a 4dr long box?

How much farther forward did you move your front hanger from stock location?

Did you center your axel on the truck before tacking in the hangers?