axles for a 3/4 ton

[GreenMystChevy]

I am getting ready to put this 8" lift on my '72 K-10 and with the tires I plan on running and towing a boat here and there, I want some bigger axles. So I am going to be looking for some 3/4 ton axles, hopefully out of a '72 so that they are the same year as my truck and I don't have to do as much fitting and linkage problems. I also don't want to have to remember all the different years I have on my truck.

My big question is: What axles am I looking for? I realize they are 8 lug, but what are they called and what are the ins and outs? I don't think I will be running into any problems when I bolt these suckers up... Thanks for the help guys.

[CPNE]

Front is a Dana 44, same as the 1/2 ton, except bigger axle shafts, etc. Rear is either an Eaton/Corporate (round pumpkin, drop out 3rd member) or a Dana 60 (both were used). You will need to do something about ujoints as the 3/4 ton axles used larger diameter ones. You can get hybrid ujoint and use your existing driveshafts or get the 3/4 ton driveshafts off your donor.

[oldiron]

How big of a boat are you towing? I have seen plenty of 1/2 tons towing boats and camper trailers.

[GreenMystChevy]

The boat I have is a 20' inboard ski boat that isn't all that light. I will hopefully be running 38.5" super swampers. I am afraid of snapping axles and u-joints every other day with the weight of the tires, the heavy boat and the angles I'll have. Now I have no real experience in this area, I am just going off of what I have heard from others and what I have picked up along the way.
I could be wrong though (did I just say that)

[oldiron]

With that size of tires you might be over powering your brakes. What is the gross weight of your boat and trailer? And what gear ratio are you running?

[GreenMystChevy]

You know, I couldn't tell you on the boat weight. I do plan on checking that out. As it is I don't have power brakes but of course that is going to have to be installed.
As far as gear ratio I currently have 4.10's but If I go 3/4 ton I will be looking into lower gears.
I appreciate all of the questions, there might be something I missed.

[oldiron]

Going 3/4 ton you are going to have to find front and rear matching axle ratios and ujoints that will go between the drive line and axles. Are you replacing the drivelines also? Will the steering linkage couple up to the 3/4 ton? The master cylinder should work ok as the front calipers are the same. Might be cheaper to find stronger axle shafts and ujoints then change over to a 3/4 axle set up. Just a thought.

[1969 GMC]

are you gonna take the truck offroading at all? since you are going with 38.5" Super Swampers, you would definitely want to get stronger axles. The 3/4 ton dana 44 front is basically the same axle as the 1/2 ton, just has 8 lugs instead of 6. You might want to find a front dana 60 to put in there if you plan on wheeling alot. if you are just gonna street drive and tow the boat, the 44 should be ok. either the dana 60 or the ho52 should be a good rearend, but the ho52 has limited parts availability, and traction aiding devices are no longer being made for it.

[bouncytruck]

GreenMystChevy, can't wait to see your truck running around! Sounds like it is going to be bad a$$ when you finish it!

[Iceman7642]

i dont know much aout this stuff but my uncle told me that my c-20 (3/4 ton) had a floating rear axle that 4x4er's all want cause if the break you can still drive on them to get you home. So, hmm i want to swap my rear end out for a c-10 for a new gear ratio and 6 or 5 lug setup. remember i don't know anything about this stuff so dont quote me or anything!!!

[Blue_71]

if you ever plan on putting a load on the axle do yourself a favor and get a dana 60 from a 79-87 (they didnt come out untill 79 in chevy) and a good rear is a 14 bolt from a 73-87, but im not one that cares about having 20 years in one truck either though

[Yukon Jack]

Another thing to think about is your springs. Your wanting to add strength by going with stronger axles but you also need to consider the strength/capacity of your springs. Unless you have custom springs made, you are probably gonna stay at about the same spring capacity when you get lifted springs. Your capacity could actually diminish a bit. When selecting a company I would recommend calling their tech department and discussing your concerns about their springs and what you are going to be towing.

[bouncytruck]

I think that the 14 bolt Semi-Floater is the one most of the hard core 4x4 guys want. I can't remember what the reasoning is though. You might be able to get by with upgrading your axel shafts & axel U-joints.

[GreenMystChevy]

I appreciate all of the help guys.
I am slowly learning some of this stuff here and there and it can be confusing. Do the 73+ steering linkages fit up with the 72 and is there a whole lot of difference as far as fit is concerned?

Also, is there a difference between a C-20 rear and a K-20 rear? Are the spring perches the same and is there any other difference?

I plan on doing some weekend wheelin but nothing terribly extreme. I also don't want to have this be a truck that I am constantly fixing or replacing parts such as axles, ujoints or anything else.

I am looking for two axles that will be strong enough, preferably with 4.56 gears, maybe a locker in the rear, and of course cheap. Hey, I can dream can't I?

[Dean]

It sounds like you need to come and buy my extra 71 K20. 4.56 gears and all. Restore the drivetrain and then set your body on it.

[CPNE]

A C-20 leaf will require relocating perches regardless of whether its a leaf or coul spring donor. Otherwise no difference.

I think the 4:56 gears were standard in I6 K20's and optional on V8's with manual tranny. I think the only ratio available with a 71/72 auto K20 was a 4:11.

[GreenMystChevy]

Dean,

Well if you are selling cheap and want to just roll it on over here, we might have ourselves a happy agreement. Just make sure to give it an extra hard push to make it over the mountains

It's something like that that I am looking for around here so that there so that shipping costs don't kill me.