9920 & 9L setup

so i guess i'll be ordering the 7xl or 8xl. 16 cells is my max. I have the IB 4200's also. Probably the 8xl as long as it will hold the 16 cells. its basically for drag racing the nitro's. But i do want a lil run time out of it. Have to prove to them that electric is fast and has decent runtime without goin to lipo's.
Thanx you guys for all the help. Any other advice you can give is greatly appreciated. The drivetrain is already hopped up so thats not an issue for me. Just making it fast, and keeping it from burning up the elctronics.