I contacted Intermountain Trains some time ago and wanted information on their 33" and 36" steel wheels which fortunately are available in bulk packs, which substantially reduce the costs of this upgrade to my HO rolling stock. Most of my rolling stock date back to the 1970’s. I have only started to buy new rolling stock recently to add to my roster.
My rolling stock consists mainly of older Athearn BB cars, Roundhouse cars, Trains Miniature cars and some later Atlas cars.
I ordered and received a number of their 33" bulk wheel packs and while the TM and Roundhouse cars were easily swapped out the Athearn cars were a different matter. The Athearn cars are a mix of metal sprung trucks and plastic trucks. The plastic trucks were no problem, however, the sprung metal trucks were a different matter.
I notified Intermountain by e-mail and I was immediately contacted by a service rep who helped me with this problem.
All of my dealings with the Intermountain service department have been most satisfactory.
I certainly keep Intermountain in mind when I purchase additional new rolling stock for my HO layout.