Could someone give me a idea of what labor time would be on replacing a crankshaft on a 1991 350SD. Just wanting to get some type of idea on how many hours this job would take. I know it is a very big job.

Thanks

r and r the motor...8 hr?
remove crank....3 hr?
resurface crank if needed 2 hr?
reinstall crank 3 hr?
total 16 hr at whatever your local rate is...$65? = roughly $1000...less (labor) if a new crank is sourced and installed.

Just off the top of my head. I am not a professional mechanic but a four decade hobbiest.

The real question is why you would need just a crank. It would occur to me that if your crank needs replacing a lot of other parts might need it too.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.