Jammin CRT x1 dual battery tray help

[Winstoncup]

Hello all
I am really thinking about flipping my rc monster mount around and setting up for rear dual lipos for balance and runtimes.
So here are my questions.
Has anyone done this? if so let me see pics please.
What trays did u use"measurements"? which ones do u recommend.
I plan on running dual 4s 5000 with my 2200 shooting for 20 minutes mains wide open.
Gearing 46 spur and 11 pinion
Please give thoughts and opinions!