Update: I highly recommend using my modified version instead, it's got a lot of fixes to the original. https://www.thingiverse.com/thing:3116823
42mm variant of the Carriage Tensioner by Old-Steve, allowing use of the original spacers and restoring the original geometry of the original anycubic carriage. I created this because I saw one of the makes on the original complaining of loss of printable area. Hopefully this resolves that issue.
Edit: I've now got this set up on two of my kossels and it works beautifully to remove the echos I was seeing in the prints due to insufficient belt tension provided by the stock spring tensioners.
I literally just did a mesh-> brep conversion in Fusion then chopped 5mm off of each side of the 52 mm carriage, and changed the badge at the top to reflect the new size.