I run smaller tires now, not quite as wide. I can probably get you some used ones this weekend, if you still need them. But, you have to promise to pick them up if I get them for you....They'll be free, of course....
We go by circumference. I think the tire size is 27 x 10 x 15, but some are 27.5...They range in size from about 84" in diameter to 87.5" in diameter, with 86.5 to 87" being the most common size at 25 PSI...Each 2PSI means about 1/8" in circumference...
I will be limited by what is already out there at the track...