I threw the fan belt on my '57 312" today and when I went to order one I noticed two different belts listed, one 44" for "HD cooling" and one 45" for "except HD cooling".

Got me wondering, why the difference? Did they have different size pulleys? A smaller pulley on the HD cooling to spin the water pump faster? Not sure which to order now. Would 1" make that much difference in adjustment?

Never noticed this before….

"The Master Cylinder"

Enjoying life at the beach in SOCAL