Re: K-28's on the 'Southern?

Mike,
Good point about 479 in Durango.
What I was thinking about was that a few months ago, Earl said that the running gear of a K-36 and a K-37 was identical, only the trailing truck and differences required to mate a different boiler to the frame changed between the 480's and 490's. So the 490's was really a low cost attempt to expand the 480 series.
Going from the K27 to the 470s was much more involved. As I recall, the K27 was initally a saturated compound with 40" drivers and the 470s were a superheated simple with 44" drivers.
The TE of the two loco types are very similar, I don't recall the wheel base or axle loading stuff.
Since the 470s seemed to be an advance of technology over the K27s, I was not sure if the RGS got the K27s because of the lack of 470s (due to the WWII draft) or the 470s were too big or too heavy or too something for the RGS.
A similarity might be that the 497 did run to Silverton for the D&SNG but was traded for 482. So slight differences in loco design might actually have an impact.
More stuff to mull over.
Doug