From: "Richard Osborne reomotorsports1@xxxxxx [Chrysler300]" <Chrysler300@xxxxxxxxxxxxxxx>
I see I am late to this thread, but I have a lot of experience with this issue and my G. These things happened approximately 9 years ago.
I popped a head plug during initial engine break-in. I then popped a block plug driving back from the Mopar Nationals. Finally, during a lunch break, while adjusting the carbs, another head plug popped out while simply idling. These had ALL been installed by the machine shop who had assembled the short block and heads.
I found that I could replace all of these without removing engine. I used a slide hammer to remove all of the remaining plugs. I then used steel replacement plugs. I searched and even purchased metric sized plugs, just to ensure a snug fit prior to the whacking. I made sure the mating surface in the block was clean of antifreeze and debris. I then coated the edge of each plug with JB Weld. For the install, I used an extra long 1/2” drive socket extension, placing the female end on the plug. Once I felt it was positioned correctly, I would give each plug a SINGLE whack. I feel that hitting it more than once is counter productive as it likely will bounce back out, my opinion, not sure if factual, but I didn’t want to do it again.
They have now been in the car for approximately 9 or 10 years with no other issues, including driving across the country and back and through the desert in 115F heat.
My 2 cents. I also carry rubber expansion plugs n the glove box, just in case….
Richard Osborne
Is there a replacement expansion plug ( freeze plug) for RB blocks that would be more reliable than those dish type welsh plugs?
I thought someone a few months ago posted something about a plug that has some kind of mechanical holder built in the plug, grabs the inside of the block like a block heater plug maybe??
I was road testing my F , one plug came off while passing a vehicle at 80mph...makes quite a big cloud of white smoke!
J.Y.