That's the thing...KP60 is not a modern axle by any measure anymore. What special tools do you need?
. Keep a junk yard set of axle shafts bolted to the UBH as spares and call it good. I'd rather deal with a sealed wheel bearing in a mud hole than tapered roller bearings as well. The fact that new axles undergo standardized testing for GVWR and such is also something to consider...castings on an 05+ d60 will be stronger than a 30 year old KP axle for sure. They're cheaper, stronger, turn sharper, and have OEM 1550 shafts available for a few hundred dollars. Show me the down side
. OEM Ford KP D60 knuckles are a known weak point anyway, so you need to almost always plan an upgrade there.
Nate, it is largely dependent on where you live. You-pull it yards in SE MI will sell 05+ D60s for a few hundred dollars all day long. One of my friends got one for $50 on a sale day.
Artec also has a ton of solutions available for the Superduty axles, as well as other companies out there.
https://www.artecindustries.com/Ford-Superduty