Thank you for everyone who responded.
Yes we have metal valve stems, I requested that when they put on the new tires. I put on the extenders yesterday afternoon. Got them good and tight and just re-checked the air pressure and with almost 24 hours I have zero air loss.
Will be taking it for a quick road trip Saturday and see how they work out. I had heard they can work loose while driving. I was advised by the tire store to add a little Loctite blue to the thread to help stop the extender from loosening up.
Again thank you for all the comments, I do appreciate it.
John