Chip, thanks for the feedback. I’ve pretty much decided on the diesel for several reasons, but mostly because I just like diesels.
However here’s a story about the inherent toughness of big V-8’s: last year, with my Avalanche (5.3 V-8), I pulled a car trailer cross country with a car on it and a full load of other garage stuff in the car and in the truck. As I was heading over the Appalachians in western Maryland, the truck started misfiring, the red flashing lights came on in the instrument panel, etc. I immediately pulled over to see what was going on under the hood. I didn’t see anything obviously wrong, and the oil level was in the normal range on the dipstick. So I looked under the truck for leaking fluids or other visible problems but didn’t see anything. I then restarted it. Engine was still misfiring on one or two cylinders with significant vibration. I continued on to Cumberland and stopped at an Autozone to borrow their code reader, which showed random misfires on cylinder #6. Counter guy said that commonly means clogged injector, so I bought a bottle of cleaner and dumped it on the tank. After another 200 miles, no improvement. I stopped again to buy spark plugs, then hit a motel. The following morning it was raining, so I figured I’d keep driving until I got out from under the rain, then changed them. #6 plug was oily and obviously not firing.
Well, that indicated a bigger problem than I wuz gonna be able to fix in the motel parking lot, and I was thinking a burned valve, jammed valve lifter, etc. But what the heck, I’d already covered 600 miles since the misfiring started, so I figured if the engine hadn’t quit by now, it would probably keep going to the west coast. And it did.
So I got all the way across the continent on 7 cylinders, loaded and towing a trailer, and holding 70-75MPH, except in the steeper grades where I had to get in the right hand lane with the 18-wheelers. Some of the sections on I-80 in Wyoming I could only hold 45MPH uphill, but that V-8 kept on Truckin’! When I got to WA I discovered I had a burned exhaust valve.
Try that in a high strung 3.5 V-6.