102D3

[luvrbus]

Jim, the 12.7 will yield you better fuel mileage than 11.1 and has a better DDEC system


good luck

[TomC]

Externally the 11.1 and the 12.7 are identical.  The only way is from the engine serial number.  Now going to the 14 liter-you can tell that since it has a narrow valve gear case in the front of the engine then the 11.1/12.7.  Personally-try to find a 12.7 in the 430-470 range for best fuel mileage and torque range.  The 500 gets a bit less fuel mileage.
The only difference between the 11.1 and the 12.7 is the crankshaft and connecting rods-just like Detroit did  with the DD15 to DD16.  Good luck, TomC

[Lonnie time to go]

Externally the 11.1 and the 12.7 are identical.  The only way is from the engine serial number.  Now going to the 14 liter-you can tell that since it has a narrow valve gear case in the front of the engine then the 11.1/12.7.  Personally-try to find a 12.7 in the 430-470 range for best fuel mileage and torque range.  The 500 gets a bit less fuel mileage.
The only difference between the 11.1 and the 12.7 is the crankshaft and connecting rods-just like Detroit did  with the DD15 to DD16.  Good luck, TomC

TomC

Can a 11.1 DD be rebuilt in some form to make it a 12.7.   If the price is good  etc....