thanks for the replies, I'll try to address them all

- stock clutch fan and shroud, replaced the fan clutch once (forgot that on my original list)

- have tried several different carburetors (not because of this problem, just because I have other 318s and carburetors get swapped around during various adventures) and the problem is always unchanged. So things like air/fuel mixture aren't real logical unless every 318 carb I have has the same problem, also unlikely cuz they run the gamut from 60's Stromberg to 70's Carter to 80's Holley models. BTW I have also been all through the ignition system and settings, checked for vacuum leaks, etc. The truck runs absolutely perfect, no hiccups, issues, weirdness of any kind. Starts instantly, runs perfect.

- it has always been this way. I bought the truck in a dilapidated state and restored it. So I don't know if it was going on before that.

- I have verified the aftermarket gauge reading two ways- with a Snap On thermometer in the rad neck and also with an infrared temp meter. It's right.

- basically, if you are driving around town or sitting in traffic it will barely hang out at the thermostat setting of 160°. If you start running down a two lane highway at 55-60 MPH it will climb a bit and stabilize around 180°. If you get on the interstate and run with traffic at 65-70 MPH it will slowly climb and climb and climb, I've let it get as high as 240° before I ran out of nerve and backed it down. If you take it down to 50-55 MPH it will come back down to normal. Again, jump out and shoot a few spots on the block with the infrared meter and it will be darn close to whatever the dash gauge says.


I've driven Chrysler products with every type of malady and in various states of disrepair, I've never seen something like this that had no reason to complain and still does. A d@#n 318 like this should be able to go to the moon and back. Frustrated.