94cc 36v torque & speed series cart

[wedge542]

First cart here, ive read on here to change the controller to a esc 48v, get a 48v solonoid, and add 2 more 6v batts and get good results, im adding a rear seat kit, springs, shocks and new batts, can i put two batts under the rear seat area ok or should i change all batts under main seat to 8 or 12 v, also upgrading cables while all this going on, has stock tires no lift just need help on hills with 4 people. thanks