Kits are designed to take Microtrains® 1037 trucks
or the BLMA® 100 ton trucks with 33" wheels and Microtrains®1023 couplers
These low riding cars look even better using Fox Valley Models® 28" wheels
Our grateful thanks go to Jim Panza for his help with these details sent privately but now published in Panza, J., Dawson, R., and Sellberg, R., 2018. The TTX Story Allentown PA, Pennsylvania Railroad Technical and Historical Society.