Best motor for 1:10 truck on 8 cells?

[Rtsbasic]

I have nothing against the 6s (it works well for me, completely different to what a lot of people have said it performs like). It doesn't overheat and wheelies my trucks up to a good speed. But I want more power, and ability to run a couple more cells. I'm not 100% sure a higher wind motor of the same sort will give more power. The 6s is torquey enough to lift the front wheels of any car at 20mph+ when I'm running on a high traction surface, and it'll keep them up to its doing around 35-40mph, with it topping out about 40mph.

Are there any other makes of motor that would give me more power for the same cell count? I'll keep the 8s under consideration, but I don't think it has the power I'm looking for (maybe I can't get the power I'm looking for on 8 cells? in a fairly heavy 1:10 car?). I can't charge more than 8 cells on my Novak Millenium so I'm somewhat limited by that.

Thanks for your input so far though guys, I appreciate it :)