The trucks under the Walthers wooden Union Pacific cabooses were very nicely detailed, but so long that they would have needed a radius of more than 36" to operate without hitting the end steps.
I lucked out because they wwere being built for a friend’s freelanced road. Otherwise I’d have been filing away at the steps.
I didn’t check the truck center against a UP CA, but suspect the same underframe was being used under several cabooses. Kadee #580 Bettendorf caboose trucks solved my problem.