The other guy 1967-72 c50 axle swap

[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.

[1976gmc20]

Food for thought:

Do you really need four wheel drive on this rig ???

Where are you going to take something this big that needs 4wd?

Like I said before, I took my old truck back into some pretty rough spots to load logs. The only time I got it stuck was dropping into a sudden soft spot when loaded and trying to get out of the woods.

In the winter before we got a 4wd pickup, I would take off the inside duals and run a set of single tire chains. Even with nothing but the swivel log bunk on the back, it would cut its way miles through pretty deep snow to get in and out of the place where we wintered. (fall and spring anyway; it was snowmobile or skis only for a few months).

[txagincali]

Originally Posted by 1976gmc20

Food for thought:

Do you really need four wheel drive on this rig ???

Where are you going to take something this big that needs 4wd?

"Need" 4wd? No.
Need Disc Brakes? Eliminate 10 lug (in this case 5 & 10) split rim wheels? ABSOLUTELY YES.

I can't speak to others but I am building a fun family cruiser/camper rig and while I may never "need" the 4 wheel drive, it is good to know that it is there as well as while in the process of upgrading the drivetrain, better off upgrading to something that is better suited to todays standards with regards to safety and/or parts replacement.

Also this rig only has 127" wheelbase, so it really isn't that "big" overall. She'll just be a little hefty.

[1976gmc20]

Originally Posted by txagincali

"Need" 4wd? No.
Need Disc Brakes? Eliminate 10 lug (in this case 5 & 10) split rim wheels? ABSOLUTELY YES.

I can't speak to others but I am building a fun family cruiser/camper rig and while I may never "need" the 4 wheel drive, it is good to know that it is there as well as while in the process of upgrading the drivetrain, better off upgrading to something that is better suited to todays standards with regards to safety and/or parts replacement.

Also this rig only has 127" wheelbase, so it really isn't that "big" overall. She'll just be a little hefty.

You might think about starting with a regular Suburban and maybe lifting and upgrading to 1 ton axles. I guess I'm not seeing the advantage of a C-50 frame with a Suburban body downgraded to a one ton. It's not like Suburban frames are really a weak point.

[txagincali]

Originally Posted by 1976gmc20

You might think about starting with a regular Suburban and maybe lifting and upgrading to 1 ton axles. I guess I'm not seeing the advantage of a C-50 frame with a Suburban body downgraded to a one ton. It's not like Suburban frames are really a weak point.

It is the grafting of a C50 medium duty front clip to the front of the Suburban body is the limiting factor. Doing that on a burb frame is rather difficult given the dimensions and shortening/fitment needed. There are quite a few start and stop threads out there on this very topic when they haven't completed the builds (mostly on trucks, but same premise for a burb).

I do get what you are saying, however my situation is rather unique. I have 1970 modified 4 door burb body on a clapped out frame (frame is useless). I have C50 chassis with 127" wheelbase (same as burb and long bed single cab) setup to run a Duramax and Allison combo. To get a C20 or Suburban chassis rigid enough to run a DMAX is a TON of work given that they will indeed bend or would need lots of boxing, not to mention clearance-ing to make fit.

Therefore running the ready made C50 chassis and downgrading the axles (since I won't be hauling gravel or produce) makes sense all around, especially given the price point I am starting at.

Sorry for the thread jacking Drewbee!

[sweetk30]

see here it is again that info would help from the start so we are not all grasping at ideas as to why you want to do it and will it work with limited info .

now that we know this it sounds like a solid plan for the drive line and why the use of a c-40 and up frame setup .

[txagincali]

I was just trying not to thread jack into Drew’s thread was all. Nearly all my info was in my thread (albeit very similar thread regarding axle swaps).

I’ll get those measurements when the light in the sky comes out. Id really like to get a solid direction in axle choices to pull the trigger.

[sweetk30]

just happens to be both your timing for the same basic questions and same lack of all details has me all confused who is who in them both is all .

[Drewbee]

wouldn't be doing my job very well if I didn't leave you a little confused Sweet.

Yeah it just so happens TX and I are wanting to do the same thing.

Great minds think a like, right?

[sweetk30]

[txagincali]

So I did a little measuring last night, granted it was dark since I knew I had to leave early, but these are the measurements I got for reference sake. Mind you, this is on a 1967 C-50 Chassis with 2.5" leaf springs so YMMV:

Starting from the front, working to the rear:

Behind front leaf hangers: 33-1/4"
In Front of Axle Spring Perch (pictured): 34-1/8"
Behind Axle Spring Perch (pictured): 34-3/8"
In front of rear Leaf Hanger: 35-3/4"

Spring perch itself (not actual axle mating surface but above it) ~4"
Outer Frame width above Front Spring Hangers: 30-1/8"
Outer Frame Width above rear Hanger (and rest of frame): 34"

[txagincali]

Originally Posted by txagincali

In Front of Axle Spring Perch (pictured): 34-1/8"
Behind Axle Spring Perch (pictured): 34-3/8"

So basically Centers on the leaf springs should be about 34-1/4" on the outers.

Subtract 1.25" from both sides, or 2.5" total (2.5" wide leaf springs divided by 2) to get the center measurements on the leaf-s themselves gets you 31.75" Center to Center.

[Drewbee]

Then I’m almost positive a Dana 60 will bolt in then as it would be an 1/8th off on each side. Anyone else see an issue with that??

This has got me pumped.

[Pvmt-Pndr]

Originally Posted by txagincali

Subtract 1.25" from both sides, or 2.5" total (2.5" wide leaf springs divided by 2) to get the center measurements on the leaf-s themselves gets you 31.75" Center to Center.

Or outside to inside will get you center to center also.... I'm just trying to add to the confusion that surrounds these 2 threads

Seriously though....An 1/8" wouldn't scare me one bit! You should be pumped about It! I would be.

[Drewbee]

Yep now I’m on the hunt. I need to find what the longest single axle wheel base you could get. I’d like to have one with a dump bed, so I’ll have those items there for possible use. A quick search didn’t show any data on wheelbase options.

[CarolinaHD]

Anything ever come of this, Drewbee?

[Pick121]

Originally Posted by 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.

I am learning about these leaf spring setups as well! This is from my ‘63 C50 manual but the general idea is the same and a pic is worth 1,000 words. Curious if the newer models also have the “canted” U bolt setup