K10 axle question

[leddzepp]

Found a pair of 73 K10 front/rear axles (Dana 44 front and a 12 bolt rear). Are they the same as 71/72 K10 axles? Any differences? Will they bolt right up to a 71/72 K frame/springs? (or a 67-70 K frame for that matter) Thanks!

[kwmech]

Yes and yes

[Ol Blue K20]

Originally Posted by kwmech

yes and yes

x2

[CUSTOM/10]

Rear brakes might be different ( wider ) , rear spring & shock mounts will probably need to be relocated.

[MDFarms]

I was told the axle shaft knuckles will be larger on a 1973 and up just yesterday fron Denny's Drivesshafts when I called on 3:73 gear set. I'm still not having any luck non my 3.73 ring and pinion that's been on order since Oct 21st.

From Denny's


I have been told that the 1973 axles that we sell will fit the 1972 but I cannot confirm this. The 1972 axles are obsolete. The 1973 axles will have a larger u-joint but will still fit through your knuckles and be the same lengths as yours.
If you have it disassembled then it is easy to measure and compare the length of each to my site dimensions.

https://www.dennysdriveshaft.com/p17...ly_1973_t.html


https://www.dennysdriveshaft.com/p17...bly_1973_.html

[52napco]

The 73 up uses the bigger 297 u joint otherwise no issues..one rear shock mount will need to be moved at best.

[leddzepp]

Thanks for the replies, just to be clear I’m talking about the ENTIRE front and rear assemblies bolting up to a 67-72, not axle shafts fitting the housing. So a Dana 44 and a 12 bolt removed from a 73 K10 will bolt right up? My concern is that the lead spring perches would need relocating or shock mounts relocating, as 52Napco stated.

[Seanext]

Front will bolt in no problem. Rear will near one shock mount moved as the 73 and up had one facing forward and one rearward. That is for 68-72. The 67 had a 3" wide rear spring one year only so I am not 100% sure the spring pad is the same for the 67 mounting. I have a 67 frame with no rear end so I can't check that to be sure.

[57taskforce]

My K20 has a ‘73 44 in it per the date code on the axle, no issues at all. Pretty sure the rear perches are 42.5 center to center vs. the 40.5 in 67-72 if I’m not mistaken. K30 sqaure body 14 bolt is the only one square body rear that has the perches in the same locations as 67-72.

[Ol Blue K20]

They will bolt in no problem. As said, one shock mount will need flipped around. Easy peezy

[davischevy]

I bought a set of 3.73's out of a 74 Blazer this past weekend. I figured I could make something work and I wanted the original positrac and gear sets.

All the aftermarket gear sets I have, make some kind of whining noise to some degree.

[CUSTOM/10]

I've done this twice, on 12 bolt 1/2 ton 73 and up going into a 72 truck. One shock mount needs to be relocated to the other side of the axle, and both spring purchase need to be relocated to make it fit correctly in a 72. The rear brake might be wider on the 73 and up 12 bolt . Front is bolt in.


3/4 ton rear is a bolt in deal.

Gary

[pwdcougar]

Good way to upgrade to front disks! I've been looking for a 73 and up front axle for a while now.

[57taskforce]

I’m telling you guys K30 rear axles from 77-91(square body) are the only direct bolt in.
I rest my case. 3/4 ton though possibly a 14 bolt floater depending on gvw are not the same perch spacing as K30, and 67-72.
All Fronts are bolt in.

Here’s a little reading. Specifically posts 17-18 the guy in post 19 doesn’t know what he’s talking about.
http://67-72chevytrucks.com/vboard/s...ad.php?t=93867

And another…

http://67-72chevytrucks.com/vboard/s...ad.php?t=50269

[BASE]

Yeah they sure weren't the same on the 14 bolt I put in my '68 K10. I was a bit embarrassed I got as far along as I did before I noticed that. Good opportunity to get the pinion angle set right where I want it anyway I guess.

[leddzepp]

Thanks everyone for your input! Thanks Gary for your personal experience and Tyler for going the extra mile to show what others have done and experienced. At least everyone agrees the front Dana 44 is a direct bolt in, and my main reason for grabbing that is for the disk brakes.

[57taskforce]

No problem happy to help! I’ve had to change perches around way more than once on my projects and for friends. Not my first rodeo by any means

[CUSTOM/10]

I have an original 72 12 bolt in my truck and I believe to be a 73 & up 12 bolt spare rear. Tomorrow or this weekend I'll measure the the spring mounts center to centers and let you know.

Gary

[Mike C]

All 1 ton trucks 73-91 squares have 40.5” spring centers, so 2 wheel drive axles will work as well in that regards. Just most of them are DRW. Dana 70 HD in duallys and the 14 bolt in C&C trucks.

[CUSTOM/10]

Measured both my 72 & a 73 12 bolt axle tonight.
57taskforrce ( Tyler ) was very close on the measurements :
72 is 40" center to center on the rear spring mounts,
73 & up is 42.5.

Also it looks like both shock mounts would have to be relocated to make the lineup correctly.

Gary

[leddzepp]

Thanks for checking and confirming Gary I may just grab the front Dana 44 and look for a 67-72 rear.

[CUSTOM/10]

If you don't have any luck finding the correct rear end, it's not that bad of a job relocating the mounts. With a 4" grinder, Sawzall, hammer, chisel you can get them off, reposition them and take it to a welder to finish it.

An option !!!!

Gary

[57taskforce]

This is true. I use a torch and/or plasma cutter to cut the old perches off about 1/4-1/2 inch above the axle tube and then grind the rest smooth. I like the ruff stuff perches and shock mounts. I finish weld mine on my own but it would be easy enough to get them to a welder if need be. It’s not terribly bad to set the pinion angle.

Shock mounts… https://www.ruffstuffspecialties.com/SBRKT-3.html
Spring perches… https://www.ruffstuffspecialties.com...hantiwrap.html

I mainly use the 14 bolt/dana 70 perches and they are really really good quality. I would guess the 44 perches would work on a 12 bolt but I don’t remember the tube diameter of the 12 bolt off the top of my head, that’s really what’s most important when ordering perches.