buy one thats not broken, that what kind
Google new or rebuilt drive shafts or go to your nearest auto parts store.
machine shop can rebuild the old one. could start looking at junkyards that might specialize in older cars
just take the old one and have the tube replaced
You could get it welded and balanced. There are shops that still do that.
It's a 72 c10 short box. I have a 327 in it