Getting ready for the first oil change in the 261. Im sure this topic has been covered somewhere here as to which oil to use, I'm thinking of useing Shell Rotella 15-40, I use this all the time in my 2001 cummins,1970 blazer and I'm happy with it. On the gallon jug, it has all the special ansi codes for every diesel out there, but says nothing about the zinc content. Will this oil be OK for a 261?
