I am beginning to believe that there is not much point in running a 'stock' or 'spec' class on road unless you all run the same motors, tires and batteries.
If you dont, you will continually have to buy the newer and improved versions every 6 months just to stay on the pace because the industry is continually improving its products.
Lipos have gone from 20c to 40c in less than a year and there has been a flood of new 13.5s hitting the market some of which perform substantially better than others.
There are no jumps in on road so there is less luck involved. Running 11.8's will make you a threat in the A Main but running 12.1's wont even get you close to the front.