I bought a Michigan K3500 Dually truck ($1200) in Nov/ 2011 that was Michigan rusted and rusted some more......BUT ...found out through digging into previous owners service records that the engine was replaced in 9/2003 at the Chevy dealer.

They spent 8k on just the engine. The truck has had 34k miles put on it since. Thinking AM/ GEP engine here.
I can't wait to see the date code when that badboy gets yanked out. I'm planning on dropping into a '01 3500HD dump truck.

Mark
'96 K2500, stock (so far) 98k miles
'01 3500HD 15k GVWR
'96 K3500 SRW
'97 K3500 DRW