Reviving an old thread. I picked up a like new actinium v1 the other day in a 8.5t, all stock. I run purpose built dirt oval cars for higher grip surfaces. A lot of guys run 6.5t, no roar rules and open speedo. Set the motor up for 30 degrees on can but thinking a better rotor is in order. Should I order a 12.7 or 13.0 or run the 12.5? Cars weight about 94oz, short course truck based. Thanks for any info.