More voltage and lower gearing is a good thing, and it lowers temps.

I have a 12t pinion I can try when the 5s & 6s land, and might get a 13 & 14t in the meantime.

Smaller Pinion (less teeth) = Lower Gearing (more torque, longer run-times)
Larger Pinion (more teeth) = Higher Gearing (more top-speed, shorter run-times)

Smaller Spur (less teeth) = Higher Gearing (more top-speed, shorter run-times)
Larger Spur (more teeth) = Lower Gearing (more torque, longer run-times)

I second the suggestion to get a Slipperential. That way if you like having thick oil in the center you can leave it and keep the even F/R power distribution without the wheelies. It is what I chose to do and I love it. You get the traction control plus the added protection to your drivetrain.

So I had a play with gearing and results were using 14t pinion, motor temp = 115f after 20 mins runtime. I had a decent amount of torque and good top end. Esc and batteries were just warm. I will post a lil vid when I get chance. But thanks to evryone for the advice!!!