the temperature gauge has been swapped to an after market thing that only has numbers. at what temperature is it over heating and at what temperature is panic "turn it off now!" mode?

From past experience /6's run on the cool side. What temp are you at?

2000 degrees. LOL You can't kill them. Should run under 200 though. What thermostat do you have in it?

It usually runs under or around 200. usually 180ish? I don't know what thermostat i have.

The closer to 200 the better the slant is known as stated to run cold

You probably have a 180 or 195 degree thermostat, you're fine.

I think everyone miss understood my post. I know it's not over heating now. I wanted to know what temps i need to be watching for if it does over heat. and when to turn it off if I have to let it cool and run for a few blocks with only water or while it's leaking.

a /6 could probably get by on air cooling alone.
good time to pull over is when the temp gauge is up and the motor is pinging?

Shut it off if over 250.

"after the next atomic bomb the only things left on earth will be dodge darts & cockroaches, the cockroaches will be driving the dodge darts.(presumeably /6 powered).Quote from comedy central. At the state fair a snake oil salesman added his concotion to the /6 oil on a test stand ran it a bit then drained it & kept the /6 running with no oil & it didn't blow. This post contributed nothing techwise to this thread but it is my cntribution for today.

I have seen slant 6's get so hot the exhaust manifold was glowing red-and still no problems.The slant 6 cannot be killed by lack of water

If I remember correctly from my old tech school days back in 1973, for every pound of cooling system pressure (15# cap) it raises the boiling point 3 degrees. Water boils at 212 deg. so with a 15# cap it raises the boiling point to 257 degrees. Antifreeze boils at a higer temp so you should shut her down accordingly. Slants are hard to kill but be safe at 230-240. toolmanmike

I broke a fan belt on one before about 7 or 8 miles from home and drove it all the way back at 55 mph. It was about 80 degrees out that day. When I got home it was still idling fine. Just dieseled bad when I shut it off and puked water/steam out of the overflow. Fixed the belt and drove it another 10,000 miles before I sold it. Oh and the stock gauge was buried the whole time I was driving it home.