Hi,
I'm not sure what you are looking for. I had at one time planned a string of 3000 series box cars in 2.5" scale. I have one completed and one almost complete.
I did not want to make all the parts for 14 trucks. I used Cannonball style cast aluminum side frames with ball bearings for the 3' 7" arch bar trucks. They were altered a little (I no longer recalled how much) so that the bolster could be made using a 1/2" x 2" steel channel (I think).
Painted and under a car, no one has not noticed the cast side frames. If you are interested in the patterns (side frames, Journal box covers, and aluminum 26" wheels are available), feel free to let me know.
I also have an untested pattern complete one-piece Andrews side frame (much closer to prototype) for the 6500 flats and maybe the tank cars and an almost complete pattern for the three-piece Andrews side frame. Both of these use the same journal box covers and wheel castings as the 3' 7" arch bar trucks.
Doug vV