A buddy of mine just picked up an 86 Bronco and the front pivot axle is pretty much shot. He would like to know which straight axle would be best to put in the front to replace the pivot style axle.

I would recommend a 44 but just want to check with you guys that actually know ford.

The pivot axle is call a TTB Twin Traction Beam. A buddy of mine has a 94 and we did a soild axle swap to a dana 44 and then to a dans 60. You are on the right track.
Chack out his site an goto the dana 60 swap.
http://www.superford.org/registry/vehicles/detail.php?id=211

D44 from a 78/79 bronco, almost bolts in

i have a 86 bronco and idid a sas and it was pretty straight forward but i would take your time and measure everything to make sure it is in their correctly i also recommend using 78 or 79 coil buckets cause the springs flex better

i have skyjacker springs for right now and i think they flex pretty well but if you want real good flex go with the jeffs bronco graveyard super flex series springs and use either after market radius arms like the james duffs or wristed arms

Get the D60. What's in there is already a D44 (although a straight D44 will be easier to put alloy shafts & stuff in, it still will end up costing about what just putting a D60 in would cost, and still won't be as strong)

D60's are expensive, easily looking at $800 - $1500 for just the axle and easily that much more to be rebuilt. This is where you have to decide what you want, a D60 will take more fab to get it under yer truck but will survive more punishment. D44 solid is easy to swap and are cheap to buy, but aren't as strong, but can be built up to take mild punishment.

I got a 78 F-150 44 to swap under my 93 F-150.... I'll be spending the next few weekends swapping it in and posting progress....