I'm disabled. I can read up on how to modify these electric carts...and buy the stuff to do it....but I can't handle doing it. So I can't do the work myself. I know how to do it, but I physically just can't do it.
Last year I began doing some research on these carts. The Bad Boy touts themselves as a 4WD cart, when in fact the cart is no more than 2 slip differential drives. So, at any given point only one wheel in front and one in the back are driving at any point in time.
I live in Pa. (Near Pittsburgh...GO PENS!!!) and around here we have hills. Now....my daughter-in-law (sweet kid) is from the Detroit area (Yeah...a Red Wings fan....made for some interesting weekends) and in the Detroit area, it's flat as a pancake. So, she thinks what we have are mountains. But they are just hills. If you want mountains, go to the Laurel Mountains....then you got mountains!!!
Anyway, I ended up with a cart guy in Lousiana building me one. With shipping cost to Pgh. of $500, he put more options and better stuff on it than any cart builder in Pa. would quote me.
Now, my cart has a lift kit, 10" tires (I think for mud 'n hills ten inch are a minimum) an upgrade to a 48-volt controller and motor with a ton of torque, and probably the most important item.....a limited slip differential in the rear end. What this is (LSD) is essentially make the rear drive a posi-traction. The only time it's not is when the cart is making an extreme hard left or right turn. (There is a reason for that...and I won't explain unless you want to know). Also, the battery wiring is upgraded to 4 gauge to accept the larger voltage. There are other modifications that I won't mention.
This cart is quiet and has gone up any gas well road or hill I want to go. (Now...if your an out of control person.....that's a different story). I did have to install a set of front disc brakes because coming down hills and stopping was getting a bit scary with only factory rear drum brakes. Much better with 4 wheel brakes.
As far as hauling....no problem with deer. I've thrown my deer on the back, bunggied 'em in and gone up any hill around here. You figure, those carts were made to handle 2 guys at 230lbs, plus golf bags....2 @ 60lbs.
Now, if your gonna stick with the stock 36-volt system, your not gonna have the torque that a 48-volt system will get you. But, if you just cruzin on flat ground and not thru mud or deep grass 'n stuff, you'll probably be just fine. I wouldn't recommend goin with larger than 10" tires with a stock 36-V system, cause it takes juice to turn those wheels.
That's my HO on this. Here is a pic of my buggy. I hauled one buck and 2 doe on it last year.