TA 340 6 pack in a 68 Dodge Dart vert

Like said
IR gun at the stat house, on the engine side; forget the factory gauges, they lie,lie,lie.
Under 30mph or over?
And yes what
cam, ignition timings,Standard or Automatic, A/C?, and stall?
To help you get started, the temp difference between the top and bottom tanks should be around 30 degrees.
No AC, no stall,automatic, cam like rest of the motor was rebuilt to factory specs. Ignition timing was just switched over to Mopar electronic set up of a 1970 to match 1970 TA motor.
I was having these intermittent heating issues according to the dash board gauge with the 360 motor. But now it is getting worse. Before, it was i termittent and on the expressway. Now it happens within minutes of dring, all the time.
Oi Vey!