The most common overheating issues with this trucks motor will be stemmed from air leaks or in proper tuning/fuel choice...
I always run that motor 1.2mm out from flush on the bottom end and .7mm in from flush on the Hi speed needle....

I recommend byron race 3000 11% lube- 245 after ten minutes
This isnt a fuel choice issue though....

Change the fuel and pressure lines
tighten the heat sink head screws
check the exhaust gasket (most likely the problem)
make sure the pipe is tight at the baffle seam