Okay guys got this H.V. MAXX 4.5 They say when you run these combos you need to use this set-up and in bold they say not to use stock e-maxx gearing.
I plan on running 2 6 cell packs 3800 what gears would you all recommend use the t-maxx spur and the steel idelers. They tranny is already single speed any help would be great.

2 6 cell packs

spur ------- Pinion
70-72 ------- 14

or

74-76 ------- 15

2 7 cell packs

70-72 ------- 12

or

74-76 ------- 13