So I installed on my 67 289a new 4 core rad with shroud and clutch fan, hi flow water pump , 180 stat with 3/16 hole drilled in the base and a Mech Temp gauge, I have no heater core just a loop. Here is whats happening , whenI drive around town the the temp only get to 160 to 170 maybe , when I take it on the Highway doing 60 mph it will reach 180 to 182 maybe as soon as I slow down it drops back to 170. Is this normal or should it not maintian closer to 180 in town or at idle.Maybe the new gauge is not working right or is it just working to good,any thoughts on this.

 

Mech gauges are very accuracte. Sounds like you have a very good cooling system set up there. Doesnt sound anythings wrong to me. But what do I know, I have only been in this game since Feb.

 

Actually 180 is little on the cold side for best operation. Why do you have the 3/16 hole in the thermo? (I believe that's what the bypass hose is for from the water pump to the thermo housing)

 

The hole helps stop air lock. You can look in the sectionabout cooling issuesunder stats it explains it there.I had a earlier air lockproblem and this worked .

 

I thought 180 was about ideal? I just picked up anadjustable thermostatic regulator for my electric fan I installed last week. It can be set from 160-200...

 

Where is this air lock article you are talking about? Does air lock attribute to the cooling system making really weird noises?

 

it sounds to me like your cooling system is working almost too well? Where is your temp guage taking its reading from?

 

Have the sensor located on on top of manifold just behind the distirbuator, is there some otherlocation ?

 

Remember you have a iron block and if oem heads and intake there iron too thats about as normal temp as you can get.

 

Ok I am going to put a new stat in and test the temp gauge and Iwill let you know how I make out.