Large Scale Central

Correct height for rolling stock

Can someone tell me what the correct prototypical height from the rails is for modern box cars, refers, etc?

I’m converting my USA Trains “Ultimate” cars (1:29) over to Kadee #1 couplers and discovered:

1- a 0.188" shim is required, even though Kadee claims only a 0.075" shim is needed on thier web site.

2- once the conversion is done, neither the straight or the droped coupler lift bar will fit and a new lift bar must be fabricated.

All this has left me wondering if the USA Trains cars need to be lowered like the Aristo cars.

Thanks,
Mark