I have the same engine/car, and delt with the same problem. Seems that it likes to run a little hot, but with very little oil content. I now run white lightning 30%, and 8% oil. The motor dropped almost 40 degrees, and with tuning, picked up alot of power. I had been using blue thunder 20%. I used the same hot plug. I also switched to a Lola body, basically puting the engine outside the body, plenty of air. I got a new pipe/header(I had been running an old HPI pipe with the rubber coupling), and the temps went down further, and it picked up more power. It's a THS pipe I got from Towerhobbies. So far this has been a pretty good setup.