I am going to build several 1:20.3 flatcars and need a good cheap source for trucks. Does anyone have old Bachmann or Delton trucks they would sell me cheap, or where can I get some without buying whole cars?
AristoCraft (Classic series) markets the former Delton sprung archbar trucks as a separate item in a blister pack. I bought them from Ridge Road Station for about $15/pair. They scale out right for 1:20, better than the Bachmann/LGB ones.
The Bachmann trucks (and USA, and LGB virtual clones) scale to 3' 7" wheelbase in 1:20, which wasn't uncommon. (It was very prevalent on the D&RGW.) They would have had the brakes hung on the outside, while longer wheelbase trucks such as the Delton/Aristo ones would potentially have room on the inside.
Aristo's trucks are very nice, and what I use myself for most of my projects. Know, however, that they come with plastic wheels. If you're upgrading to a high-end wheel like Sierra Valley, this isn't an issue. If you want metal wheels, I'd think about buying some of the Bachmann flat car kits. They come two to a box, and sell for around $40. That's just a bit more than the Aristo trucks, but you get Bachmann's metal wheels. Granted they aren't the top-of-the-line metal wheels, but they roll quite well enough on my railroad, so whose to argue?