need measurement for 69 440 stock crank pulley

[73dart360]

I am having a heating issue on a new engine ,I used the pulleys that came with it ,I just spoke with the previous owner he said the crank pulley is under driven ,I just measured it ,I think I got 5" or 5,25 the engine is a 69 this may be part of the problem in stop and go traffic.

 

[wedge69]

Stock is steel and alot bigger than that. Say around 9 to 11"

 

[Mr Belvedere 30144]

I have a 69 440 in my Belvedere and no cooling problems. My crank pulley is 7 1/4 and the water pump pulley is 7. I also have an electric pusher fan for summer days and any traffic issues.