Thank you for all of the input. I was able to run the car for a good 25 minutes yesterday with a temporary rubber plug in place. No major drama, which is a good thing. I may run it again just to make sure all is well. Then I will instal a new replacement plug. I would also like to confirm that this is supposed to be a 1 3/8" plug? This is the plug that goes in between the exhaust ports on the side of the cylinder head. Is this a 1 3/8" and not some odd size? Below is a response I received from Jim McMulln who cannot respond via listserver. Thanks again, Richard Osborne Columbus, OH I feel your paine.Bob is right use brass ( alloy of copper and lead ) or better yet bronze (alloy of copper and tin) I haven't used JB weld but it should work.I use permetex #3 dries hard,but I am a old timer.You can get the plugs at a marine supply shop.Good idea to use a temp rubber plug to break in the engine and find any other faults. If you find something that causes you to pull it back out you will kick yourself for fitting the new plug in with the engine in the car.Good luck.please forward to the list server as I cant get there? Jim McMullan 300F calif [Non-text portions of this message have been removed] ------------------------ 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/