Well whatever it takes to put he other puley on t would be worth doing. I would be surprised if it was cure. After 40 years of doing this for fun and a living I can asure you it will be something just that simple that will cure it. IT IS ALWAYS SOMETHING SIMPLE!
Sometimes it is so simple it doesnt sem to be worh doing. Last one I work on was exactly simialr problem . Ran ok when moving but overheated or almost so in traffic and when stopped. It was a 440 build I had done as per my book Old Reliable. The car was a 64 Didge and it was a beautiful job. I went to lok and saw the wrong pulley instaled , not what I recommened. The stream of excusues ranged from wouldnt make THAT MUCH DIFFERENCE to I could get one to fit. Since it was my motor (They are ilke my own children so i really do car) I went to the wreckers and boughtthe pulley I had told him it needed. It was just 1/2 " smaller diameter for the water pump. O took it home and painted it and then gave it to him he installed it. END OF PROBLEM COMPLETLY> Why because both the fam and the water pump are now running fast enough to move cooolant and also make sufficent airflow through the rad even at idle.
That was three years ago and nary a problem since. it never goes above 195 regardless.
D
