6.2Blazer said:
A couple things to point out:
- From the best of my knowledge, a front 30-spline 10-bolt was only offered from '89-'91
That is correct. However, the 28 spline housings are the same as the 30 spline, which means that you can use a 30 spline carrier and axles in the older housings.
- While a 30-spline alloy inner axle may be prenty strong, what do you do with the stub shaft? You are pretty much stuck with the same size stub, granted you can get alloys ones but the physical size still limits the overall strength.
The stock D60 stub is 30 spline, which is weaker than the alloy 19 spline stubs. That is why folks upgrade to 35 spline stubs on the D60. D44/10b apps are a bit screwed, however. A 30 spline (1.312") shaft will physically fit through the D44/10b spindle. In fact, International used 30 spline stub shafts on the 73-80 Scout with the D44. Unfortunately, they are about 1-1/4" shorter than the GM stub

This isn't a big problem - you could easily have Superior or another axle manufacturer make a 9.94" long 30 spline stub. This would be great, except nobody makes a 30 spline hub lock.
- Along with the above, I also wonder about the size of the u-joint yokes on these axleshafts. Granted you can get better material but you are still limited in how "big" you make the yokes.
Yup, but the alloy shaft yokes are stronger than the stock carbon steel D60 yokes.
- If you get fancy alloy axleshafts, you pretty much have to get fancy u-joints also. I used to have a 30-spline 10-bolt front axle.......never broke the shafts but broke the axle u-joints. Again,you are limited as you can not put a bigger u-joint in.
Again, 4340 760-size u-joints are much stronger than the standard Spicer 806's used in the D60.
- 10-bolts and Dana 44's have balljoints instead of kingpins, and typically do not hold as well to bigger tires. Plus they have small wheel bearings, smaller brakes, etc...
Nobody is suggesting using a 10b or D44 with 38+ inch tires, even with alloy axles. It would be doable, provided you were very careful, but here is the point where a D60 (with alloy axles

) is better. Of course, if someone runs a 10b with alloy axles and u-joints, breaks it, and thinks swapping in a D60 with stock parts is going to solve their breakage issues, then they're delusional.
- At least on a OEM open carrier, you can NOT switch from 28-spline to 30-spline shafts. The side gears will physically fit, but the openings in the side of the carrier itself are too small to allow the larger 30-spline shaft to fit. Not sure about the aftermarket carriers though.
That seems to be what I recall as well...
- A 10-bolt with alloy shafts and blingy u-joints.......significantly cheaper than a Dana 60?? Not real sure about this, I guess it depends. If you are not in a hurry and do some searching you can find a complete good condition Dana 60 for $500, slap a $300 Lock-right in it and it will hold up pretty good. On the other hand buy a $100 10-bolt, $500 Detroit locker, and $600-$800 for alloy shafts and fancy u-joints. Okay, so you have two axles that hold up about the same regarding axlestrength but you just spent more on the 10-bolt, plus you have it's other weaknesses to deal with.
First, find me a $500 D60.

Good deals can be had, but this is by far the exception rather than the rule. Figure a grand for a good rebuildable D60, a couple hundred bucks for gears (unless it happens to have the right ones already), more cash for wheel bearings and such (since it probably needs 'em). Then more money for a driveshaft. Another $250 for a lock-right. Then another $600 for a Detroit after you realize that is what you should have bought in the first place rather than being a cheap bastard.

Most folks don't have to buy a 10b or D44 - it's already sitting under their truck. So now, you have to realistically figure out what you are going to do with your ride. Most people don't go bigger than 35's or 37's on their rig for a variety of reasons, including cost, daily driveability, etc. For these folks, upgrading the 10b or D44 will be more cost effective, as well as having more ground clearance (important, since they aren't using huge tires), a better ride (less unsprung weight) and better mileage (less weight, less internal friction). For guys who are planning on going bigger than 37's (which by definition means you don't really care about daily driveability or mileage - this will be a mostly trail rig), then it is probably wise to get a D60. If you like to flog it, plan on spending money for D60 alloy shafts, blingy u-joints, etc.
