Here's a list of some multi-class special events iRacing has posted for the first quarter of 2021
https://members.iracing.com/jforum/posts/downloadAttach/2641764.page
Jan 22-24 Daytona 24
Feb 12-14 Daytona 500
Feb 26-28 Bathurst 12
Mar 26-28 Sebring 12
Apr 23-25 Nurburgring 24
