emaxx gearing?

[ill_tempered_02]

I have a hacker b50 10xl and a mm in the mail and I want to run 12-14 cells and I was wondering if anyone had a basic idea for gearing for it. it weighs about a 1/2-3/4 lb over stock. I want to have an Idea to be close and so I can go from there. I just don't want to blow up my mm right away. also the battery (6 or 7 cell packs) must be wired in parallel right? thanks