[Yachts]

are outmr series 60s 12.7 or 14's

[br549hoffman]

I believe the 12.7 60 series is in 2003 and earlier it is a pre EGR " Exhaust Gas Recirculation " engine and is there a big difference in it and the 14L that is in a 2004 and above .... primarily on fuel milage my pre EGR trucks get around 7-8 mpg  the 14L get's around 5 mpg .... So i'm guessing "and that's all it would be" your coach being and 04 would most likely have the 12.7 L because the engine would have been installed in 03 .....  but newell would have the answer to that ...The Detriot diesel corp. class 8 engine was usually a "series 60" starting back in the early 90's they were 11.1L and more commonly 12.7L and then there were different generations of refinement ie. ddec I,II, III, IV up to I believe late 2003 early 2004 where they switched over from 12.7 to 14L to meet BHP " Brake Horse Power " ratings due to EGR also I think they also switched to ddec V with was the last update in development, they carried that version of engine through 2008 where the "DD" engines came into play. The DD13 is 13L and the DD15 is a 15L and there is a DD16 also  ....  Some useless trivia for you .... there were pre EGR 14L starting in 2000 they came in at 575BHP/1850TQ and 550BHP/1850TQ they are rare I own one factory installed, but I would advise against buying one because parts like Turbos and engine specific parts and VERY hard to get.