Hi Rolland, I use a Mopar Performance 180 degree thermostat - larger opening. My old H w/air overheating problem was mostly solved with a new fan clutch. I'm having a overheating problem with my 62 Sport w/413 and air. A new radiator core, thermostat and flushing hasn't helped, so I probably need a new fan clutch. I will be interested to hear what others in our group have to say about water pumps. Doug ----- Original Message ----- From: RWestra@xxxxxxx To: Chrysler300@xxxxxxxxxxxxxxx Sent: Monday, July 30, 2012 2:03:41 PM Subject: [Chrysler300] 300 water pump. I seem to remember discussion about water pump differences between A/C and non A/C cars but I cannot find any documentation on the website. Does anyone recall this discussion or know the differences? It seems to me that impeller diameter and number of blades were the variables but I cannot recall the details. Also do the letter series 300's have a special thermostat requirement? The temperature gage keeps rising on my H. It never overheats but reaches the top of the normal range. . Rolland Westra [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to bob@xxxxxxxxxxxxx or go to http://autos.groups.yahoo.com/group/Chrysler300/join and select the "Leave Group" button For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/search.htm#querylangYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: Chrysler300-digest@xxxxxxxxxxxxxxx Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/