Re: Ho Scale Atlas U.P. 1950's 70 ton Hart Ballast Hopper (Trucks)
The Union Pacific HK-70-1 hoppers rode on 70-ton Barber S-2a trucks. Notice the wedge shapes inside the bolster ends. The newest HO version of this prototype is offered by Rapido. I feel it is well proportioned, but falls short of proper wheel base.
I tried answering your question on Saturday but my post still hasn't showed up.
Tahoe Model Works
Carson City, NV
please visit www.resincarworks.com/tahoe.htm