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Rocker assembly 135ftlbs rocker box or housing is 35ftlbs
You may be thinking of a M11 Cummins
280-390
One
44 quarts is the norm for the M11.
44 Quarts
Depends on which motor it has. The 11.1 and 12.7 Detroit Diesel 60 Series, Cummins M11 and N14, and various Caterpillar motors were available options for that model year.
Any 15W40 diesel-rated oil is fine.
Do you want to have no power at all? The M11 is a vocational truck engine... the way the truck is geared with the C15, I seriously doubt you want to stick an M11 in there. Not only that, but that's a post-ACERT truck... you can't put a pre-ACERT engine in it legally unless the truck was purchased as a glider kit.
The M11.
Cummins is the manufacturer.
n-14 rod and main bearing torque specs