You may want to consider changing the rear tires as the track dries out,also.
Suburbs,bar codes,... SO many choices. Mount up a mess of rears and try them.As traction changes,so will your choices of tires will be. Some rears will dictate a slipper change,as well. Traction is going fast. PERIOD. Tires is 70% of the go-fast formula.
I have seen one -run rear tires in the garbage can,mounted.They didn't work,that time,that day.

Clay changes during the day.Dust build up and the way the surface dries out.
Freshly swept? Gooey? Watch for wheelies!
Power to the dirt? YEP!

Wheel spin? No fun.

I have smelled Paragon tire stuff in an indoor DIRT track many times.WD-40 works OK,too. Overnight in a baggie makes 'em super squishy and the clay will not stick to the tires.

It's a game to see what works.

We all hope to find the blue groove,then it's just like running on hi-bite asphalt or carpet. Then the tires make noise.

Have fun and go fast.
I used to race,now I just bash. EYE LOVE R/C!