ok, I can get my hands on a set of m-715 axles for dirt cheap (under $200 for the front 60, rear 70, complete, and a spare front complete)

BUT, they have apparent downsides in being all drum and closed knuckle front with 16 spline shafts and narrow tubes.

because of the narrow tubes I assume that I can't grab a set of ford or chevy 60 outers to fab on (can I?)so what are my options to re-tube to a larger od?

Are there any options here or am I stuck?

there's other issues with m715 axles like the whack bolt pattern, the closed knuckes (which you mentioned) and I think the rear is even a 2-piece axleshaft the the oem AMC model 20's. For what it would cost you to re-do the front Dana 60 into a modern axle, you could buy a modern axle. rear Dana 70's can be had for less than the loose change in your couch. Personally, I'd skip on the axles, even for $200.

you make good points, but the cost to regear a standard axle would put the cost up another 300-500 over the cost of the axles.

These axles are tough as anils but have a ton of downfalls....I am truing to figure out if there are any easy answers around these downfalls.

not worth is,more cons than pros

I have a dana70 closed knuckle front that has me in the same predicement. has the right gears in it, I have no problems with the closed knuckle design cause I can't turn that sharp anyways. the drum brakes and six lug pattern are the problems. I was thinking of boring the knuckles out to fit a unit-bearing hub from a dodge (I have my old ones to try it with) then fit disks somehow.

Well you can look at this way, $200 is not a bad deal for a rear 70 with 5.86s, and two sets of 5.86 gears and carriers for a 60. OK you get boned on the rear 70 being 6 lug. The 23 spline thing is not all that bad, they are still fat axles. I believe that the rear 70 hubs can be swaped to ones that have 8 lug. The fronts I would keep the gears/carriers and sell the rest to a M-715 for around $100-$150. Even if you change the front over to 8 lug, you sill have a stub axle problem, they will and do snap off right after the splines.

ok, I know that it is a narrow tube/shafts. can the carier and gears be swapped into a chevy, dodge, ford 60 front? If so, do I have to stick with the smaller spline count or can I swap to 30 spline in the changeover?

yes you can use the carrier and gears in a Chevy, Dodge or Pre 77 Ford 60. If you are going to use 35 spl axles you just need to swap the side gears. The Pre 77 Ford will be low pinion and use 30 spline axles.