The pair in service right now are the 3000-3009. I ran them last night and the night before on the 11 Tilden job. Considering the total lack of maintenance and the fact that they are being run 24-7. They are still running remarkably well. As engineers we really dislike using these engines, especially in winter. When running they are hot as hell, but if you sit loading you freeze. The dynamic brakes are not full range. That means under 20 MPH they don't do anything but make a lot of noise. The cab noise level is horrendous. The independent brakes barely work, and setting automatic is by pure feel because the gauges don't read properly. I like the analogy, would you prefer to haul a full load of bricks down a mountain in a new modern truck, or one built in 1972 that hasn't had any decent maintenance since the 80's? The b###h for us is, the damn things are made so well, they won't die.