68 GMC 3/4T D60 rear to 72 K10 swap?

[franken]

Hey,
I've done some reading and wonder if a 68 3/4 ton 2 wheel drive Dana 60 rearend will bolt in in place of my current 72 K10 rear.

What I read was the 68 rear had a spring perch center width of 42.5" while mine should be 40.5. I only found one post saying the spring pad width was different.

My truck is a mongrel made up of parts from 72, ??, and it seems and 85, but the spring hangars look original.

The 68 is in the scrapyard and I'm looking at $150 to get it. Its missing drums, axles, and hubs. But, since the D60 is common, I may be able to troll the yard and scavenge the axles and hubs. Maybe even a later disk setup.

The gear was 41 9 which divides to 4.56. I was thinking more about a 4:10 rear with my planned 5.6 1st (~4.5:1 max low range).

I'll need to locate a front diff to go with it, or rework my D44 6 lug.

So, are the spring centers off, making this a no go, or is the price bad? Good?
Wait for a decent deal on a front/rear combo? I'm in no real hurry. Still working on the NV4500/doubler/NP205 combo.
Any opinions on 4.11 vs 4.56 combo? I'm looking at a 2-4" list and no huge tires. Probably 33s.

Any comments or advice welcome

[Mike C]

4 wheel drive trucks and Longhorns have the 40.5" spring centers. Two wheel drive trucks have the 42.5" spring centers. '73 and newer trucks also have the 42.5" spring centers 2x4 and 4x4 except for 1 ton trucks which are 40.5". But if you use a newer truck axle, the shock mounts will need to be moved.

There are no bolt in options except from another 4x4 truck in the '67-'72 range. But moving the spring perches is not that difficult a job.

[franken]

Well, at least I don't have to drag it from the scrapyard, I guess.

Hmm, I've read that early 73+, at least cab and chassis 1 tons also had the narrow perches, but the difference between 2x4 and 4x4 I never stumbled upon.

Thanks!

Back to the scrapyard... One of my favorite places.

[kwmech]

I'd pass on the axle with all the missing parts and find a complete, where are you located? I may be able to hook you up with a complete with the ratio you need

[franken]

DFW Texas...

[franken]

Strange. I measured from the outer spring edge to the inner on the other side and got 40 inches exactly. Then I centered the tape measure at the same spot to measure from the spring center to center. Same thing.

This was from just in front of the plate the U-bolts bolt through on the top of the springs.

I'm pretty sure the U-bolt and plates aren't quite normal since there's a 2" block and I replaced the plates with (I think) those from a Jeep.

As I recall, normal would be square U-bolts and a rounded bracket on the underside of the axle tube.

I'm going back tomorrow with a tape measure and printout of other vehicles using the D60 to make sure it won't work. Hopefully the truck and rear will be gone, or the measurement will show it won't work, thus solving my problem.

If the measurement suggests it'll fit, I'll troll around looking for axles, hubs, etc. since this diff was pretty commonly used.

Now I have to find the distance between the wheel mounting surfaces...