O.K., forget the comment about conversion of lbs to psi. The little boy I mentioned is also not going to bed until around 11:00p.m. and then waking up at 3:00 a.m. My thought process is not what it should be. Best regards, Richard Osborne >>> "Richard Osborne" <richard@xxxxxxxxxxxx> 08/15/04 01:33PM >>> Good Afternoon, While driving home from cruising at the Mopar Nationals last night, the right front freeze plug popped from the G's engine block. It was late, we had the baby in the car and were in a less than desireable part of town so I drove the 3 miles home, pretty much non stop. We had driven almost non-stop for 80 to 90 miles at between 50 to 75 mph. It popped while slightly accelerating to change lanes (very slight acceleration, didn't even open secondaries). I just installed a temporary rubber plug in and pressure tested the system. After 20 minutes of measuring, it dropped 1 psi from 25 to 24 psi. I see in the 1961 service manual that you are to pressurize to 15 lbs. I am not sure of the conversion to psi? My results, however, seem to be acceptible. Do you agree? If you remember, a couple of months ago while breaking the motor in, the plugs in the cylinder heads popped. It is interesting that the first plug to go in the head was also right front, coincidence? After mic'ing everything, I was confident that the machine shop had installed plugs that were slightly too small. I have driven the car maybe 500 miles since fixing the head freeze plugs. The temperature has seemed to be good, never pinged, never had a problem starting when hot. No evidence of water in the oil, even now. The same machine shop installed the plugs in the engine block. Could this be the same problem of too small plugs? I am concerned as the car has now lost several cylinders (I just got it out to wash all of the antifreeze off of it). It will not idle now, where previously, it idled very smooth. It is also backfiring slightly through the carb (I think right side carb (which feeds the left side of the engine), but not sure) a little. I will pull all of the plugs and do a compression check on all of the cylinders. Who knows, maybe something will become obvious once the plugs are removed. What am I missing? What else should I be looking at? Can the freeze plugs be replaced while the engine is in the car? I didn't have time to survey as I need to watch our little boy, he loves riding in the G, so this is motivation to fix it. No Woodward Dream Cruise for me... Please advise of your thoughts and experiences. Best regards, Richard Osborne Columbus, OH To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm Yahoo! Groups Links ------------------------ Yahoo! Groups Sponsor --------------------~--> Yahoo! Autos. Everything you need to know about buying or selling a car. FREE Quotes, 360° Tours, Research, Blue Book, Compare Vehicles, Buy Used http://us.click.yahoo.com/kEZsdA/bwnGAA/YiGOAA/8LmulB/TM --------------------------------------------------------------------~-> To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> 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/