What is safe maximum sustained RPM that I can run my 602.962 and not worry that I am beating it to death?

I have read elsewhere (not sure where right now) that at 50% to 60% of red line an engine can run indefinitely.

Is that true for a diesel too?

3000 RPM = 80 mph in my 300D.

Redline for a 602 is…I don’t even know the answer to that.

3750 RPM is 100 mph for me…can I run that speed for an hour or more someday when I’m cruising across the lonely southwestern states of AZ and NM?

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1993 W124 300D 2.5L Turbo, OM602.962
2000 Chevrolet Cavalier, 2.4L DOHC
2002 Ford Explorer, 4.0L SOHC
2005 Toyota Prius, 1.5L

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