NASCAR Gear Ratios

Does anyone know what rear end gear ratios teams use? I recognize they vary from team to team and track to track. That said, maybe someone can provide a range of ratios that might be used all season from the shortest tracks (Bristol/Martinsville) to the super speedways (Indy, Talladega, Daytona)? And with any amount of luck someone can tell me if a team would use a different ratio for Indy (not banked) and Tallagega & Daytona (banked).

I know at Martinsville they used to use a 6.50. Track banking doesn’t matter so much as top speed does. You want a gear low enough to pull all the way to just under the rev limiter without hitting it. Restrictor plate tracks are different because they can’t rev like a regular motor, so I’m not sure what ratio they use. I would think they would need a taller gear to hit the high speeds they do with less RPMs. High RPMs let you run a low gear. Of course, NASCAR now mandates gear ratios, so teams don’t have the option to run the high RPM timebomb engines like they used to. That’s one reason you don’t see many engine failures anymore.