gearing advise for x12 7.5 w/84 spur!!

[09 lex 250]

alim going to the regionals and current electronics are lrp sxx tc spec w/lrp x12 7.5 need advise to keep temps down along with some power as well.also im getting some slop in the front arms. you can slide them both back and forth while mounted on the car.is this normal on these cars? any advice would greatly be appreciated

thanks in advance