Thanks a lot for the info. Any ideas on my coolant issue?

Thanks a lot, that helps a ton...

Merged your 2 threads on the same topic

a glowing manifold is waaaaay advanced, ur running super lean basically. actually your fuel just isnt burning all the way, then its flowing into the manifold and being burnt there. do some tuning, check your dizzy. ur prolly reaching full advance at 2000 rpms or so, getting crappy burn rate readings from the 02 sensor, not to mention conflicting signals from the other sensors, and ur computer cant compensate the timing accordingly. get that right or say bye bye to your exhaust valves.

this would also explain the over heating, as u are essentially flash boiling your coolant, and possibly creating more air pockets in the passages. get a new thermostat, check you timing, make sure its dead on (retard a few * if anything) then purge your coolant system.

hit back with results.

red hot exhaust
 

Hi!
A glowing exhaust manifold clearly indicates that your ignition setting is RETARDED and needs to be advanced a few degrees.an old tip for setting the ignition was to set the throttle to a fast idle and turn the distributer either way until the revs peaked --this was the best way of finding a starting point to reset the timing , if it " pings "( sounds like coffee beans dropped on a empty biscuit tin = pre-ignition ) under heavy/hard acceleration then it's too far advanced and needs to be retarded (backed off ) a little .I know from experience -- a guy had a van that had the same red hot exhaust problem. this was fitted with opening and closing points system ( very-pre electronic system ( 1970's ) and the points had closed to 0.005 thou. -should have been 0.015 thou. which meant that the spark was late( RETARDED) and therefore the fuel was still being burnt as it was being pushed into the exhaust system ,making the exhaust manifold red, I opened the points (advancing the spark to correct setting )and cured the problem.

^^^my bad. *hangs head in shame...

totally thinking backwards there, thats what i get for staying up late with a beer in my hand, then trying to post...FAIL.

Also, be sure to check the ignition timing per the TSRM. This means vehicle is at operating temperature, you have no diagnostic codes, and the jumper is in the diagnostic box. Failure to meet all these requirements will almost guarantee a false reading of the ignition timing.