SBA 800 Gearing with 2" Challenger?

My '15 SBA 800 has a very different set up for sea Level (U.P. MI) compared to mountains. Sea level, per the owners manual as follows:

10-66 weights, black primary spring, blue black secondary spring, no change to helix or chaincase gearing for elevation, assuming you already have a 2" track.

While there are always small ways to tweak individual performance attributes, the factory settings (in the owners manual on Polaris.com) are usually a pretty good all around set up. Doesn't matter who made the 2:, it's still the same size lug and same effort to spin it around the axles.

Here is a link to the manual -
https://prdvehiclepubsdata001.blob.core.windows.net/public/OwnerManuals/SNO/9925088.pdf

Edit - re-read your post. If your stock gearing is 23:40, that tells me you are running a 1 3/8 Cobra. So you will need to change gears to 20/42 when installing the 2" track. Same 72 pitch chain. I change mine back and forth between 1 3/8" and 2" depending on where I am riding (Mtns or Midwest). Works/runs/performs great in both set ups. If you are running a different year SBA, then just go to Polaris.com and get the owners manual for your model year.

I changed my 17 SBA to the 19/40 after I put a 2" track on it, you will need a different chain. 68 pitch I believe. This gearing works great in the flatlands as well. No clutching changes are necessary when swapping to the 2".