I have had both Ford and Ram. The Ford diesel is an International/Navistar and they have been making diesels since Mobydick was a guppy but I drove a big rig for 20 years and mostly Cummins motors. I like the interior room of my Ram much better than the Ford. My Ram and my Ford have nearly identical horses but the Ram seems to pull better. The Ram is also quieter even though I have the 12 valve 5.9. It just seems to be better built.
No it isn't.
Ford stopped putting Navistar engines in their trucks at the end of 2010. In 2011, Ford switched to the 6.7. The 6.7 Powerstroke is Ford's design.
Navistar/International made 3 engines for Ford.
(1994-early 2003) - 7.3 Powerstroke (International T444E)
(late 2003-2007) - 6.0 Powerstroke (Navistar VT365)
(2008-2010) - 6.4 Powerstroke (Navistar Maxxforce 7)
2011 - current) - 6.7 Powerstroke (Ford Scorpion engine)
That said, after owning a variation of all 3 manufacturers, the Ram is far superior in terms of interior finish and comfort and the Cummins is a much more reliable and robust engine.
OP - go to Ford if you want but take it from me (a prior 20 year long Ford fan).... they will help you until you buy a truck. Good luck after that. Can't say much differently for GM.
My local FCA dealer is a joke. I will drive 100 miles out of my way to avoid them.... however, my Rams have spent 1/10th of the time at the dealer as the Ford and GM equivalents. YMMV.