gentleman
anyone know if chrysler made 2 different water pump pulleys (ratio) for a 72 340 or any 340's? were there different ones for a/c and non a/c cars? running out of ideas!! having a low speed (at idle) circulation problem even with a new high flow pump, t-stat, and new "everything" to do with the cooling system, to include 6 blade steel clutch fan, stock shroud, desert cooler radiator, and even a pusher electric as insurance etc etc etc. when i raise the idle up to 1500-2000rpm when sitting it sucks the temp right down so its circulation. this is only at idle for extended idle in traffic on hot days. once underway im good. motor is a newly rebuilt top to bottom 416 so no gunk in block heads etc. it actualy ran warm even before the rebuild as well but never overheated. only thing i can think of left is maybe an underdrive pulley rotating to slow? it is a mopar stamped factory pulley on it but unknown on size? any ideas based on the above what it could be? highway driving is fine at 200-210 max hot days and 65mph at 3100rpm.
anyone know if chrysler made 2 different water pump pulleys (ratio) for a 72 340 or any 340's? were there different ones for a/c and non a/c cars? running out of ideas!! having a low speed (at idle) circulation problem even with a new high flow pump, t-stat, and new "everything" to do with the cooling system, to include 6 blade steel clutch fan, stock shroud, desert cooler radiator, and even a pusher electric as insurance etc etc etc. when i raise the idle up to 1500-2000rpm when sitting it sucks the temp right down so its circulation. this is only at idle for extended idle in traffic on hot days. once underway im good. motor is a newly rebuilt top to bottom 416 so no gunk in block heads etc. it actualy ran warm even before the rebuild as well but never overheated. only thing i can think of left is maybe an underdrive pulley rotating to slow? it is a mopar stamped factory pulley on it but unknown on size? any ideas based on the above what it could be? highway driving is fine at 200-210 max hot days and 65mph at 3100rpm.
