newer 6.7 reviews ?
 

i think of looking into are first 6.7 Cummins for the farm to tow goose neck horse trailers with would like to know what your guys reviews on them are or should i just buy used and stay with the 5.9 Cummins ??? and do the 2013 Cummins have that DEF shit on them i heard they do and some say they don't, so thoughts ??