160 is good, I would actually try opening up the valve. You'll probably find the temp doesn't move. If you're paranoid like me and 2Sav, run a pressure releif valve set at 15 or so with the overflow to another overboard dump. I'm afraid of milkshakes too, and for $75 bucks or so for everything you need to add it in, cheap insurance.
Thanks about the Moo boat. Pretty much done. Tunnel ram tomorrow, and some minor touches, she's finished.
I'll cya on the lakes this summer probably, I'm kinda hard to miss.
Ray