66 Dart, 408 runs hot. HELP PLEASE!

Ran the car this weekend for the first time at a track, and it did very well! temp was 95+ with roughly 20% humidity. Ran 195 consistently in the staging lines, i hit 200 once while hot-lapping it. id leave the line at 195 and by the top of the track it dumped to 185 and would hold it until i got to the staging lines once again. Ran a 12.41 @ 112 on 225-60-15 street tires. Im happier with it, so Im going to let er rip taterchip! Thanks everyone for the tips and ideas. much appreciated!