Welcome super lurker...
When you say 'blew up' what do you mean? did you spin the bearings to the point of damaging the spindle? Did you damage the threads on the end?
Most of the time, these parts are reusable.
Regarding replacements, from recall, about 40 years ago one of my coworkers had a 69 c10. He changed out all of the 'wearable' part like ball joints, tie rods, bushing from 1/2 ton to 1 ton components. Said they were interchangeable so if that's the case, you should be able to find a spindle, if needed, from 1/2 ton to 1 ton and it will work.
If I'm wrong, which I have been, look for someone more knowledgeable than me to flame me silly, then watch as I fall from the sky into a pile of smoking twisted wreckage.