Yes - A shallow lip which I think you can see in the zoomed in screenshot from your pic. Be very careful not to grind away or disturb that as the new expansion plug won't be supported properly or seal right if ground away.
Have you tried prying out the remaining plug?
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
