I want the tender I'm building to have power pickup from both rails without changing the height of the donor flatcar's body-mounted couplers.
Bachmann's replacement part pages show that the tender trucks from the 2-4-4-2 and 2-8-0 Consolidation are the two candidates I can choose from. Are either of these the same height as the Arch Bar Freight Trucks used on their flatcars?
Well I took a chance and ordered a tender truck from the 2-4-4-2 and it's perfect: A bit longer than a standard freight truck, has electrical pickup, the couplers line up great, and it fits tightly enough onto the flatcar to hold it in place without glue.