Added heads, heat went up...Normal?

Hey guys, haven't posted in a while but I thought I'd ask this. I recently add some Frankenstein heads to my ctsv and noticed the engine temp went up about 12 degrees. I'm running a stock thermostat. When I run my car at the track I usually go from about 200f and that's during the summer. Its plus 8c degrees here now and running at almost 200. Thoughts? Also, anyone ever use water wetter products?

Cheers