Forgive for being inexperienced in the hobby. I have some passenger cars (Walthers Superliners) that need closer coupling for the diaphrams to connect. I currently have Kadee No. 5s on these and they provide closer coupling than what came factory on them. I thought 58s would work better.
If you have broad enough curves, why not use a coupler like the kadee #23’s. The head on the #23 is the same as the #5 the only the coupler shank is shorter.