TTI Exhaust Hangers

For my 1973 Dart I have a pair. So wanted to know what others did? Innstall on seat belt bolts or on the factory hangers.
I never got under there yet as rain for next week or so with a cat 1 hurracane on the way.
Note} My car has both hangers since it is a 340 car. So thinking it would be silly not to use them.
Or is it not possible?