bought an AM 2923 Scale 4-8-4 but the same model just came available in AC Hi-Rail. Trying to decide if I should get the Hi-Rail version.
If I want a ATSF Mikado, I'd have to bash an AM flyer light with Hi-Rail wheels.
Do you go scale wheels or stick with Hi-Rail everything and plan the layout to accommodate scale equipment?
Stick with the scale wheel version you have. AM locos with scale wheels do great on code 100 and code 138 track.
Regarding the Mikado, you can get the Flyonel TMCC Mikado rather than modify an AM light Pacific. The Flyonel Mikados are beautiful models, but I can't comment on how accurate they are for ATSF's stable.
I use code 138 rail and run both high rail and scale wheels. I'd be happy to have code 100 rail and run all scale wheels, BUT that would mean no Flyonel Legacy steamers such as the Challenger, Y-3, or Berkshire, all 3 of which I love. It would also mean never running any of my vintage Gilbert stuff which I do enjoy once in a while although I am primarily a fan of scale modelling. Of course the key is what do you plan to use for turnouts. Unless you plan to build your own, turnouts for 138 are very limited (mostly unrealistic #5's) whereas code 100 has lots of great choices for many radii.