Those numbers are perfectly fine- my Hv6.5 has a kv of 3100, and also runs on 16.8v. It does run hot, but then my truck weighs a ton and the motor is just a 380 in 540 clothing.... you should be fine.
I ran it last weekend two set of lipos and the venom samrt temp shows that max temps were(motor) 37'c at gearing 22/64.So i quess that everything is ok......i should gear it down a bit cause tires start to balloon a lot
To help reduce tyre ballooning, you can stick some duct tape around the inside of the tire- you have to remove them, turn them inside out, run the tape around then a couple times, then turn them back to normal and glue them onto the rims- helps alot or so I hear.