Re: K-27 Running Gear

K-27s were converted to "D" slide valves first. One of the Loree Report"s recommendations was to change them to piston valves with and outside type of valve gear and that would then make them easier to superheat.
The first four had inside canted piston valves which now seems to have been done so they could keep the Stephenson Valve Gear. Apparently 456 was the lone experiment with this idea - all others converted to piston valve received Walshaerts Valve Gear when the cylinders were replaced. K-27s were all outside (steam) admission - I was in error in my Mudhens book describing inside/outside admission.