13's, 14's vs. 9's , 10's

[Irace007]

Before the 9 inch slick there was a "street " tire M&H had 10/12 inch rear tires that had different compounds . Like the slicks..The .1/10 rule i believe was from the late 60's early 70's in Jr Stock (Tom Kasch)
Dave Young would have some info on that .Also we had to dial the MPH too.Take away the sand baggers