I am replacing a 6.0 that got totaled out last week monday. I stop at a local dealer to take a 6.4 for a ride. it seems tp be fully stock, couldnt find any mods anywhere on the truck, tires were even continentals like oem stock. The only things i noticed with it were a boost leak and some turbo noise.
The noise got me curious being twin turbo, its hard to explain, almost like an engine hunting. when the turbos spool up one of them sounds like it just doesnt want to spool right away. was happening from 1600 to 1900 just curious if this a normal sound or something to stay away from.
Havnt dealt much with 6.4 but have had 7.3 and 6.0 for the lst few years.

thanks
Duddy