Just curious Kern Dog...what engine problems are showing up past 300k. We only have one 5.7 in the family...we will probably be looking at what your considering but hopefully far far down the road...130k in a dodge magnum R/T. All our pickups have cummins.
At 59,000, one of the lifters (Cyl # 4) associated with the MDS failed and would sometimes stick half open, allowing reversion into the intake and a very poor running condition. The shop had to pull the head, replace the lifters, pull the rod and piston, hone the cylinder and screw it back together.
Since then, only the regular maintenance along with a few small items. EGR valve, thermostat, A/C evaporator fan assembly and spark plugs. Otherwise, this 339,000 mile engine is completely original. I've only changed the coolant twice.
I have to keep it compliant with the California smog check limitations. I am seriously considering a move out of this state but I plan to swap engines long before I leave here. Exhaust mods will have to wait.
The paint and body are still very good. Everything still works in this truck. There is no rust anywhere, no crash damage. I don't like the way the newest trucks have gone fully bonkers with the infotainment screens, lack of CD players, knobs for shifters plus they seem so dang huge! The way that I feel today, I want to keep the truck and continue to use it as a daily driver and work truck. The current engine has served me quite well, it is just tempting to step it up a bit when the time comes to replace the mill.