The two bits of evidence the site points out are (a) an anonymous inside source saying a vehicle is in development, and (b) a displayed time in Ram press photos. If you look closely, some of the Ram interiors show the time 7:07 on the infotainment display. This corresponds with the Hellcat engine's 707 horsepower. Allpar further speculates that the vehicle will be Rebel-based due to a preponderance of the number in Rebel interiors. This wouldn't be the first time FCA has hinted at a future model's power via infotainment time, either, as it did so with the Challenger Demon.
There are some holes in this theory, though. We went back and looked at the press photos of the interiors, and the 7:07 time shows up on Bighorn Rams, too. And not every single Rebel interior has the time. There's at least one that shows the time 8:29, which appears on various other Ram interior shots. Also, while FCA did manage to make a full-time all-wheel-drive system for the Grand Cherokee Trackhawk to stand up to the Hellcat's ferocious power, we doubt that drivetrain would be used in a Ram, since it's a much different application. The final nail in this theory's coffin might be that the head of Ram Trucks communication told us that the times in the images are a "complete coincidence" and that "this theory is all speculation."
All things considered, we think the odds of a Hellcat-powered Ram reaching production soon, particularly an off-road version like Allpar suggests, is pretty iffy. We wouldn't rule out some sort of Hellcat-powered Ram completely. At the very least, putting a Hellcat V8 into a two-wheel-drive Ram for a street truck would make loads of sense. It would be less expensive to develop compared to a Raptor competitor, it wouldn't have any existing competition, and it could capitalize on the history of the Viper-powered Ram SRT-10 from the mid-2000s. And as we've seen, FCA has no problem stuffing absurdly powerful V8s into everything it can, from Charger to Durango to Grand Cherokee.
So, don't count on a Hellcat-powered Ram yet. But it might happen eventually if history is any indication.