I have this kit from DIYeboards on a custom deck. http://www.diyeboard.com/36-dual-motor-6-wheels-allterrian-electric-skateboard-10s5p-p-596.html
My question is what ways can I improve the board maybe new motors or motor mounts on it so I can adjust belt tension, if so what motors and mounts would work? I love the kit and the wheels I have in it I just need it to have more hill climbing power to get it some of the larger hills in my area.
Upgrade the battery pack to name brand 18650’s at 12s 
12s may not work with that Esc. @DarkZed1 You could get a set of new motors. But the bottleneck could be your ESC as well. 10s5p should give you 50A continuous with the cells they use. That is generally good enough for most hills. So that means either the motors are too small or the ESC cannot deliver 50A continuous power for long enough. I think changing to VESC would be the biggest upgrade you could make to that board. Look at Vanda vesc and run these motors in BLDC mode. I suspect things should improve quite a bit.
How would I go about that swap from Esc to Vesc?
I have that same board but I bought from ebay for much less but with 6s4p battery. It’s not made to do AT. It was loud and I would get 18mph, I thought i made a mistake buying it, but I knew the risks involved. I swapped the wheels to regular longboard wheels that it came with and it was alot quieter with way more torque, went from shitty to bitchin. They really built this board for regular wheels. You’ll need to get alot of new things, 2 VESCs 63mm motors, mounts maybe even belts.
Not easy to upgrade anything they offer (unless it’s torqueboards.
The esc limited at 50a. The Li-Ion pack is limited at 50a. The drive train will suffer when increasing performance (no belt adjustments possible).
If you replace the Li-Ion, you are limited by the esc. If you replace the esc, you are limited by the Li-Ion. If you replace both, you are limited by the drive train and will have to replace that. If you replace the drive train, you will reach speeds where the 0 angle trucks will cause stability issues, meaning you have to replace everything except for the esc and Li-Ion you may have already upgraded. In short, the entire board is useless once you’ve outgrown it.
If you’ve outgrown this board, I highly recommend selling it and saving up money for a trampa or mbs build.
Not much to upgrade, your limited by everything.
Want new trucks? You need a new mount. New motor? Need new ESC
Also the motors are to high kv if its the same 270KV motors they used on the other boards, so no vesc with stock battery.
So on, i would just leave it as is and sort a new board together since your going to replace everything at the end.
I got the kit from Chargiot for $600 with their custom deck and grip tape. I don’t think it’s a bad price for it since it also came with the wheel conversation kit. I will throw on the street wheels and see how it feels.
Best way to upgrade with all the limits on the board would be to gut it and replace the components with quality parts and build a board using that deck and and enclosures and wheels That would probably be your best bet