72,000 on my 12 truck. 170,000+ on my 07 truck. I am really a maintenance fanatic on both. More so on the 12 model so far. Both are tuned. 12 has tons of mods and I idle a LOT. Tranny fluid flush at 30,000 miles and again at 70,000. Oil every 4000-5000 miles depending on idling time that period. Use Amsoil. Clean S and B filter every few thousand miles, maybe like every 15,000 or so (just a guess) only when it is visually getting dirty. I know I could go longer but why push it. Just flushed and swapped coolant for second time. Swapped 180 degree thermostat for a new 180 Duralast thermostat. Did a much better flush this time around. Had AC electric fan on radiator changed under warranty a few weeks ago because it went out. Again, TONS of idling in very high heat area. Heated seat element went out on drivers seat bottom. I bought an swapped both the top and bottom even tho it was the bottom one that went out. Again, TONS of idling and I run the heated seats all the time because it helps my old aching back. I had the brake pads changed at around 20,000 miles IIRC because they squealed. They were still good. Put Hawk pads on it and no squeal. Had Bilstiens put on at 15-20000 miles to raise front end. Stockers were still good. Think one may have been blown. Lots of driving on some really badass bumpy Texas lease roads. No real issues.
On edit: Sorry, I guess you just asked about the engines. My bad, LOL. My engine and trans have had ZERO issues with LOTS of miles and idling and tons of full throttle passes of slow moving big trucks.....and F150s haha. I also change my spark plugs every 30,000 miles whether they need them or not. On both my Hemis.