Polaris Racing has released setup sheets specific to the Indy 600 for both ice and terrain style racing. Part numbers and information regarding a carbon fiber over structure reinforcement kit and tunnel brace kit are shown below, followed by specific set up pages for ice and terrain.
There are also setup tips for MIRA enduro and USSA ice oval racing on the Polaris Racing website.
Indy XC Carbon Fiber Over Structure Reinforcement-1
2019 Indy XC Tunnel Brace Kit
2019 600 Indy XC Cross Country ICE Racing set up sheet