Been a 'horsepower hunter' most of my motoring life, whether it was a 105E Anglia with so much skimmed off the head I had to put extra washers on the spark plugs to stop the pistons hitting them and pockets so deep in the pistons for the valves you could lose a small child in them, and the only way to run the engine was to mix 5 star fuel with glow plug fuel, or a 500 BHP 6.0 V12 with a manual gearbox, my quest for more horses limited only by my wallet and I never even looked at a diesel for car use, my experience being only with heavy commercials.
Having said that the old saying 'there is no substitute for cubic capacity' has always held water. Big capacity/low power output engines are under stressed and tend to last for donkey's years and the LC 4.2 is no different. I think in the scheme of everyday life, the Toyota 4.2 turbo seems to have a nice balance between power/reliability and longevity, mine now approaching 1/4 of a million miles and never been 'opened' adds credence to that statement.
I love big engines and think the 80 with the 'big six' is well matched, I still drive it quite hard and it never fails to impress whether loaded or not, I would need some serious reasons to carry out the mod to the Cummins, but would love to see it done and have a test drive.
regards
Dave