Those of us running headers are doing just that!

I remember Ralph and I had a conversation at Elsinore once (in early January) about how cold the water was. I commented how Moo always ran about 140 no matter what, where or when, and his wouldn't didn't go over 100 or something that day. Same setups, no logs.
The logs, however, are aluminum, and I think that might not be a good idea to divert the cold water from them.
Are you running a thermostat? Your temps seem higher than I've ever gotten with logs. I've never gotten Pickle over 160-170 with your setup.
To be honest with you though, at 180-200, you're right in the normal street range for the engine, and I for one would leave it alone. That is the exact range your engine was designed, tested, developed and intended to run at........

Ray