As others have said , make sure timing and carb are correct first .
I used to spend a lot of time on circle tracks in SC , NC and GA . We didn`t run a thermostat , but we did run restrictors/orifices in place of the tstat . With nothing in there , the coolant circulates too fast to get good heat transfer from the engine to the coolant ..... you have to slow it down . The only way to do that was to play with various sized holes until you found what worked .
We also ran pure distilled water and water wetter ....
antifreeze and water mixture wasn`t as efficient on heat transfer as was just water . Plain water also didn`t make the track slick if/when you blew a hose either .
Now for the street , on my ERA with a 482 here in GA and the Carolinas , I run a 180 degree tstat with 3/16" holes ( 3 ) drilled in it at the top to allow some circulation when cold and to help get rid of air .
Summers here are in the upper 90`s to sometimes low 100`s and I run 200 degrees in traffic and that temp is not a problem . Personally , I feel if your traffic temps are in the 200 to 205 range , there`s not a problem .