The other guy 1967-72 c50 axle swap

[Drewbee]

I decided to start a different thread as IÂ’m not trying to overload anybody elseÂ’s.

I appreciate the information IÂ’ve been given and maybe IÂ’m just not understanding.

I do understand the basic information on the width of the spring perches and that the Dana 60 has the perch built into the housing.

I donÂ’t understand the c50 chassis, but IÂ’m trying to. Looking at it, the c50s are not like the 1/2 ton or 3/4 ton as they do not have a arms and coils. Instead, they have leaf springs over an axle beam. This makes me wonder if the Dana 60 and 14 bolt would bolt in. The other thing that makes me think itÂ’s possible, even though the frame is a different style, is that the same cab is used on these trucks as the smaller trucks (1/2 ton - 1 ton).

I have a 4x4 cummins build I was doing with my 72 but I may go a different route if it wonÂ’t be too much more effort.

[sweetk30]

go grab a tape measure .

measure the center to center of the leaf springs on the c-50 and current axle you want to swap in .

measure the width of the leaf springs on the c-50 and if there 2.5-2.75 range you will be good to go on this part .

if they both match up then yes it will swap in .

the rear will need to be cut off old shock and spring mounts and weld on new ones to line up with your needs .

[Drewbee]

SweetK30 If I had one, I'd do that in a heartbeat instead of asking on here.

I don't have access to one, and don't want to go buy one just to see. I was hoping someone on here had done it and could chime in.

[Pvmt-Pndr]

You don't have the C50 frame with springs or you don't have the D60?

If you don't have the frame or springs I can measure my C60s springs for you tonight if I remember. I'm completely guessing here but I have to imagine the C50 and C60 frames are pretty much the same. My frame is reinforced too, I'm not sure if that makes a difference. I read on here or stovebolt that the normal with of a big truck is 34".

If it's the D60 you don't have there's tons of places to find that info.

[Drewbee]

Pvmt Pndr

Thanks!

I dont have the frame.

If the springs on the frame are 32" centers then a dana 60 should be able to bolt in. Seeing as the cab is the same whether it's c10 through c70, I bet the leaf springs end up the same distance apart as the 1/2 ton and 3/4 ton trucks.

I understand this is arse backwards as I'd be putting 1 ton axles on a 2 ton truck, most sane people probably dont do this.

However spending a few thousand for a running c50 without seeing if someone else knows is too rich for my blood.

[Pvmt-Pndr]

The way I took it was you already had the C50 ready to do a swap. That's why I asked.

You've already explained what your truck will be used for so I don't blame you for ditching the overkill suspension you don't need. In addition to that using a 1 ton drive train only makes sense too.

I don't like to throw money away if I have it or not. Admittedly I have done that quite a few times with my truck but never over anything huge. The latest is my $344 AVS2 edelbrock carb I have sitting on a table waiting for me to wrap up my interior before I slap it in. I have no idea if it'll bolt on or not.

[Drewbee]

Gotcha glad we’re on the same page.

Yeah I’m really thinking about doing this and doing a crewcab conversion. If I got the right c50 I’d have all the big items,

I have already:
Good cab and bed from gmc c1500.
Front Dana 60
14 bolt
12v cummins
Nv4500
and Np205

C50 would provide:
Long chassis
Second cab

Then it’s just putting it together. I know there’s other items as well, but I think the list above would be a damn good start.

As for your carb, lets keep our fingers and tossed crossed that it bolt on for yah.

[Pvmt-Pndr]

I'll see what I can do tonight about those measurements. I'll get inside and outside measurements for you. I plan on working on the interior some more today if my back is holding up still.

If you come across a C50/C60 with a sleeper on the back I'd be interested in it! I've been kicking around the idea of putting one on mine but instead of a bed a bench seat or a couple of buckets so I can get all my girls into it when we go to mud bogs.

[sweetk30]

i wasnt trying to be rude but that info would have made a huge difference in my info i gave you . good luck on the swap and keep us posted .

worst case a simple set of custom leaf spring hangers could be fabbed up and put on the frame to make your axle fit on the front and even use std 73-87 style springs for more option on ride quality .

this guy sells good stuff pre made or fab parts .

hangers with adjustment http://diy4x.com/product.php?product...cat=250&page=5

he also does a few styles of bushing and tube o use and make a shackle hanger . then get a pair of his beefy shackles and there is your front end .

[Pvmt-Pndr]

Rear outside to outside 43", center to center 40", inside to inside 37".

Front outside to outside 33 3/4", center to center 30 5/8 ish, inside to inside 28".

Spring width on both front and rear is 3"

[Drewbee]

No worries sweetk30. And diy4x makes some good stuff!

Thanks Pvmt Pndr!

That sounds close.

The rear is 40.5 center to center so a 1/4 inch on each side isn’t terrible. The front actually surprised me. If I’m reading it correctly the c60 frame is narrower than the k10 frames.

My Dana 60 is 32 centers and the c60 30 5/8.

Even if you could gain that extra 1 3/8 with custom spring hangers, I don’t know if there’s enough room on the passenger side of a Dana 60.

Hopefully I’m overthinking it.

[Drewbee]

Hey just thought of something. What year is your c60?

[Pvmt-Pndr]

The difference of 1-5/8" would be divided by 2 making it roughly 3/4" that would be needed per side. Going with 2-1/2" leaf springs (shimmed in) would make it 1" less that needs made up. So now you're at 3/8" you would have to figure out

[Pvmt-Pndr]

My C60 is a 1969. My wife has a 1972 K10 also

[Drewbee]

Gotcha! Yea I see what your saying. I wish the guy who built the k50 had more info. I seen some pics but not much info but I understand he does it as a business. From the pics it looks like he bolted these right in. It definitely looks like he used the c50 front springs.

I'd link the thread if I could as he's a member of this forum.

[sweetk30]

if your doing custom hangers and shackles like i said it dont matter the difference as you are making the brackets fit the axle and frame needs .

[Drewbee]

Yeah I’m just trying to wrap my head around it.

I’ve watched rtech fabrications YouTube video on the k50 crew cab several times and I know for a fact now that he uses the factory spring hangers at least for the front but I think the rear as well.

The video shows the front end completed before he puts the axle in and it has the unique front leaf spring hangers these trucks have.

The frames are a little narrower than the light duty trucks but taller. I may have to wait until I can actually be around one in person.

This is fun looking at what could be. I’m wanting this truck to be my daily and be buried with because I just can’t justify 70k for a new diesel. When for 70k I could have my own unique ride.

[Pvmt-Pndr]

I came to the same conclusion about a new truck. I'm a diesel guy, the price of new or fairly new doesn't appeal to me. I can afford it but I don't want to. Hence the reason I'm working on a 50 year old truck that I fell in love with. She doesn't do anything great but look good everything else can be upgraded over time.

If you need any other measurements on a frame of either trucks just let me know. Just don't ask suspension or drive train ones on the wife's truck. Not much is still stock.

[1976gmc20]

The front actually surprised me. If I’m reading it correctly the c60 frame is narrower than the k10 frames.

That makes sense because the medium truck frames are straight ladders front to rear, and the rear has to be narrow enough to fit between big dual tires and massive springs on both sides.

I wrangled my stock C-50 into and out of some pretty rough places in the woods to load logs. I did get stuck in a couple soft spots but I'm not sure a front drive axle would have helped any when you get that much weight buried.

[Drewbee]

I’m back to thinking this will work on the front end as well.

If it’s 30 5/8 centers on the c50 with 3” wide springs, then using 2.5” springs brings them out to 31 5/8 centers with bushings, which is only 3/8 from the required 32” for a Dana 60.

3/8 divided by 2 would be 0.1875 on each side. Is it dangerous to pull the leaf spring over that little? That’s 3/16th of an inch.

The next option is custom mounts like sweetk30 but I’m a stickler trying to figure out how people do things and I can see the k50 had its unique spring hangers. I doubt he changed the spring perches on the Dana 60 as I’d think that would mess up the drivelines.

Thoughts?

[sweetk30]

1ton down are bolt in front and rear springs to the frame hangers .

not sure on older 72 and back . but the 88c-70 i have in the driveway has slipper spring mounts on the rear of the front leafs .

so make sure you know what type of system you have as this might mean make your own brackets for the safest and best mounting system .

[txagincali]

Originally Posted by Drewbee

I’m back to thinking this will work on the front end as well.

If it’s 30 5/8 centers on the c50 with 3” wide springs, then using 2.5” springs brings them out to 31 5/8 centers with bushings, which is only 3/8 from the required 32” for a Dana 60.

Thoughts?

So jumping in on this thread as well, and some food for thought. C-"50" have 2.5" wide leaf springs. Whereas the Topkick/6500's mentioned are indeed 3" wide leafs. I have both and was wanting to swap my 88 Topkick axles over to the C50 to get juice disc brakes but the gearing wasn't the best (5.42) although much better than the 6/8 2 spd rear in it originally.

I got my C-50 chassis out of storage yesterday and have it in the yard to work on so I can get better measurements if need be, but one thing I did notice was that the front leaf spring taper from the rear frontward. So while it is 34" outside to outside in front of the axle (31.5" centers) it was narrower toward the bumper by nearly 3/4" and wider towards the rear. I'll get exact measurements tomorrow to follow up on since I don't have a cab or other body parts in the way.

[Drewbee]

Sweet can you expand on what you are saying? I’m slow. ��

Also I’m interested to hear more of slipper spring mounts. That’s new to me and has me intrigued as I love learning new stuff.

Thanks for sharing your knowledge.

[sweetk30]

med and heavy trucks dont use shackles like 1ton down . the back end of the leaf slips back/forward in a hanger is all . so if you tried to put in a narrower spring pack it would give side to side play and make things move in a bad way .

pics from my 88 gmc 7000 / chevy c-70 dump truck with 66k original miles

1 = front hanger front spring bolt in to hanger

2 & 3 = rear slip hanger spring rides in and a bolt holds in on the bottom from just droping out if lifted up .

4 = rear spring front hanger . upper is slipper and lower is tourqe spring holding the axle square .

5 = rear slipper with safety bolt like the front .

now i hope this helps understand why some trucks you cant just put narrower springs in and shim them easy .

[Drewbee]

Thanks Sweet for the pics and explanation. That's a cool design and you're right that wouldn't work to shim in narrower leafs. Aight guess I'd have to put this on the back burner for now.