hey guys I tried searching but couldn't find the answer I was looking for.

can I build up the stock dana 44 axles to handle 37" or bigger tires with lockers and maybe ~350HP?

I have an '84 k5 with dana 44's (despite all the info I've come across saying they only used 10 bolts in '84) and I was curious how big I could go tire wise if I upgraded the stock 44s VS swapping in a dana 60/14BFF. I'm not planning on putting big tires on the stock 44's. I would like to be able to run at least a 35 or maybe a 37" tire or even 38-44s if I could but I would be happy with 35-37". the stock gears are too tall for this (3.08:1) and I want to run selectable lockers.


the following is more info on the blazer but not really important to the original question so you can skip if you want.
right now the truck has a 220hp goodwrench 350 mated to an upgraded 700r4 and what I believe is an NP208 case (defiantly not a 205 or a 203). the shop told me the trans now will hold up to some hard use vs. how they come from the factory. my plan was if I can build the axles enough then I would do the gears and lockers now and down the road do the lift and tires. if not I'd leave it alone and save for a 60/14bolt or probably just find a whole different rig to do a ground up ridiculous dedicated wheeler build on since if I'm going to start down that road I might as well go to a bigblock/turbo400/atlas case with custom driveshafts and maybe go straight for some rockwells and a set of 49" interco tires.

 

i would say even 35s are pushing it. i ran 38s on 10 botls for years but really had to kinda ease into the throttle and off in the mud. first time i punched it in 4low on gravel i busted the front shaft. if it were me id do whatever size tires you want and leave the axles open and see if they even hold up stock

 

There are parts available to make a very strong 44, but once you start getting into the hardened shafts, higher spline counts, etc, the cost involved starts to quickly approach and then exceeds the cost of a decent used Dana 60 with maybe a marginal strength increase over the D60 on the internals only (comparing a stock used D60 and a fully built D44).

My advice will mimic abig84's. See what you can do with your stock axles while saving up for a Dana 60.

 

stock 44 will handle 35s, my ten bolts are and i beat the **** out of them, and for a locker get a limited slip or leave it open, or your going to be breaking axles and joints.

 

Well I wasn't planning on building the axles to the hilt yet. I just want to figure out if I'd be wasting money to get gears and lockers for the 44s. The idea was to get gears and lockers, then latter lift and tires. Then I'll upgrade other parts as neccisary. I don't do rock crawling, mostly mud and snow but next year I'm moving from Oregon to Colorado so the wheeling scene might be different down by pueblo than up here.

 

A locked D44 can break with just 33's on it. As Z stated, if you want to do something to the diff, a limited slip will be much more gentle which will extend the usable life of the axle.

Still, IMO, you are throwing money way by upgrading the D44 if your intentions are to run 37's. It would be money well spent to save it up for the D60/14BFF.

 

well if I'm going to be doing an axle swap then I'm going to shoot for at least 44"s. after reading a recent issue of 4wheel and off road about a sububan on 46" mickey thompsons I'm not even sure I'd be happy with 37"s after all. maybe for a while but I know a guy with a toyota on 38"s so I have to make sure I can show him what's what! the axle swap would also solve the annoying issue of the rear axle being narrower than the front.