When my stock nt-16 engine is throwing down good power it runs in the low 300's.

I just tore it apart and cleaned everything after 2 gallons of running and no signs of damage or wear...except the bearings.

I have had the engine hit 570 F and then stall because the fuel boiled in the carb and it still runs fine....although wont idle for long! That was a mistake though...I didnt have my smart temp turned on and was running in deep snow....wide open for like a min. solid.

My fuel is 25% nitro "Backyard Basher"

I think you can lean your engine out a little more....even if you do screw it you can re-build it at customrccars for like 40 bones!