This is huge to me, I say the bigger tune you can tow with the better. I like having power when I am towing and not having to worry about EGT's.
So does anyone know can the 6.7 run cool like the 6.4??
I dont have any info to back this up, but my guess is no. The turbo is a lot smaller (even with both compressor wheels), and from the diesel power test that I saw, as well as the tunes that they are making for them, I think they run out of air MUCH quicker than the 6.4s do. Less air is gonna mean higher temps. Just a guess though. They will probably run as cool, but probably not at the same power level.