This is a tutorial I built years ago, showing how to:

- Remove the shell on N scale Kato F, E, and PAs
- Install Red Caboose (now Fox Valley) short shank and medium shank Unimate couplers
- To achieve much closer, more prototypical coupling distances

These couplers can still be found if you look around, Fox Valley still has the medium shanks on their website URL .

Here's a PDF to a Google Drive document of mine that explains further how I had to use the asymmetrical Unimate coupler pairings on the Kato E and PA:

https://drive.google.com/file/d/1c1-rmuBE77eDMRR-zd9415HsTWtdL-zu/view?usp=sharing|

Here is a Trainboard thread where we discuss this topic in more detail:
https://www.trainboard.com/highball/index.php?threads/n-scale-close-coupling-alternatives.118355/page-2

As of 2025 Jan 9th, Fox Valley Model's website still has some of these Unimate couplers (they still sell products separately from Scale Trains). Go to https://shopfvm.com/ then click on "PARTS" towards the bottom of that page. That will get you to https://shopfvm.com/collections/parts
I just checked, and they sold out of the short shank couplers. :( I'm glad I stocked up on them. They still have medium shank version available.

Enjoy!