Cooling question?

[6camaro9]

I usually dont post alot on here I learn more by just reading but I have a little concern with my car and I thougt with all the knowledge on this site somebody could help. This winter I made a few changes to my 400 sbc and now it is running a little warmer than it has in the past. Installed a set of Dart aluminum heads, added vintage air with a front runner system, did away with mechanical fan and now just running a electric fan with a shroud on a griffen rad. I have the condensor and a trans cooler mounted on the front of the rad. My first question is will the aluminum heads run a little warmer and if so how much warmer. The temp gets up to about 190-200 now sitting in traffic as where it use to run about 170-180. Second question is what is a temp. that is too much for aluminum heads. Thanks for any help or suggestions.

Richard