You call a 6.0L a good running engine? What are you smoking???
Yeah they're fast, but they proved time and time again that they're not as relaible as the 7.3L PSD they replaced.
You just can't beat the stubborn reliability of an IDI. Dad's '90 (in my sig) has 354,*** miles on it, and has never had the factory seal cracked on anything but the water pump, starter, and thermostat. Although, we did replace the tranny aabout 12k ago, but it wasn't the original one anyway, and was replaced once before dad bought it in '98, so it don't count.
If I ever own anything other than an IDI, I want it to be a 7.3L, 6.4L or 6.7L PSD.