Reverse flow heads, not going to happen. I'd like to see a GT45R mounted up there.
From my understanding while talking with a former Ford diesel engineer, the 6.4L was originally designed with reverse flow heads, but the engineers couldn't control heat dissipation along with heat damaging the paint finish on the hood and overheating various underhood wires and electronics. I am sure the 08'-10' enhanced EGR
heat wasn't helping.
So, the 6.7L get the more efficient reverse heads, but it seems that the turbo system did cost potential performance. Compounds would have been better, but obviously not where Ford wanted to go with it..
I am guessing any aftermarket turbo that does appear may have simular heat issues unless some sort of hood venting is engineered along with it.