Cat Challenger 85C engine replace options

I have the engine apart in my shop out of a Challenger 85C for a friend and customer. It is a 3176B with now a bad crank and head from a rod bearing spinning. So far, we've had no luck locating a good runner out of a salvage tractor. My thought now is to find a good running truck engine and swap over components (engine mounts, oil coolers, etc.). I've done this on other agriculture engine brands with a fair bit of labor and am wondering just how big a job this might end up being if we can't find a tractor takeout. Also, can the later C engine work in place of the B model?

Cat Challenger 85C engine replace options