it all depends on what your looking for in your x-mod, for acceleration id go with the pinion and gear labled (most tourque) how ever since the S.B. motor is already a torque beast id go for the lowest gear ration (i.e. pinion set labled 'highest horse power") because youd have the top speed of the low ratio gears but because of the motor you'd prolly beable to spin the tires as well... if your not a fan of excessive tourque you can retime the motor for more revs bout 30% or so and a lil loss in torque... if your serious about retiming you'd wanna search fer "retime" or "motor mods" at this forum.. hope it helps
so do u plan on modding the C.B. motor, if you do tell me how it goes,(i havent got my xmod yet) so i havent done Ne mods, btw if you you could post a toutorial (if you want, cuz every1 wants 2 try this, but no1 has specificly explained how) at my thread "MiniZKiller" im sure this setup of yours would surely Be a miniZ Killer!