Backhalving?
I agree with guitar jones...fitting the biggest tire you can was what i was always taught as better...the more tire, the more traction, and hopefully a better hook...thats why small tire guys who run fast get respect get credit for it, because its harder to hook the power on the smaller tire...but if you can run as big as you can why not? a backhalfed car running 13's is goofed, but if your planning for 10's (even if you dont get there at first), youll definaty be planning for even faster in the future...do it once man, thats all i have to say...but then again, you really havent told us anything about your setup