Back-flow fuel filter part

I decided today to change the oil in the ‘73 Survivor and while at it see if it could use a fuel filter as well. To my surprise it had the back-flow preventing rubber seal still intact, I had never seen one and unfortunately the new filter didn’t come with one, thought I would share for others like me who had never seen a real one ☝️.

 

Too cool!

 

I haven't replace one in many years, but I believe that the actual GM filters had the valve. and most of the aftermarket filters didn't.

 

Everyday Performance still sells them..

 

I believe the delco filters all come with that. I always cut them out, its just a restriction.