[68C15]

if you look carefully at your shaft assy from front to back while on a hoist you will notice that it goes straight from trans back to the CB. then off to the pass side to the diff. I'm guessing age-rust & high torque load killed it. they are not too hard to replace & I dont suggest going with a 1 piece shaft. long wheel base makes for a long shaft which is quite prone to damage from road rash. not to mention the harmonics & lower torque threshold. look at a semi or other heavy duty truck, they all have at least one hanger bearing.