Its called profits! I hate to be cynical, but pickups are the most profitable vehicles made by the big 3. For some odd reason people seem to gobble up trucks, no matter the price. As long as consumers continue to do so why put any engineering effort in which costs money and erodes profits. Just raise prices, the masses will come with their 72 no I mean 96 month loans. Though I will note ram sales are down significantly, and I'm starting to see rebates return the trucks back to their true value.
I'm surprised GM is considering a new V8 to put in production. Especially when V8s are being abandoned by most manufacturers in favor of turbocharged inline-6's. I won't be surprised if RAM ends up offering their 3.0 turbo-6 in the HD trucks of the future as a base engine. Seems like a logical choice to replace the ancient 6.4v8, unless the 6 is more expensive to make, then the choice will be to keep the v8 because profits! I'm going to be very surprised to see a Cummins gas 6.7 end up in ram trucks, unless its cheaper to make than the 6.4v8, or they think they can charge more for it.. Especially when RAM probably has more profitable options in house.
If we see a Cummins 6.7 non-diesel in a ram; I expect is some alternative fuel, hydrogen most likely (not gas). This to meet 0 emissions targets and range targets in a HD truck, without going BEV But a 6.7 is too inefficient compared to a fuel cell/electric motor setup to make it a reasonable choice with the small amount of hydrogen that you can store in a truck (low energy density). I'm just not seeing where the 6.7 will fit into rams future lineup, unless its really cheap to make, or they turbo it and eliminate the diesels.. Or we could see the 6.7 gas show up as a mid range option as an alternative to the Ford 7.3 and a minor step-up from the 3.0 i6/6.4 v8.