1952-59 Ford Fuel additive in a flathead

Fuel additive in a flathead
Do I need to be using a fuel additive to replace the lead in unleaded gas for my 53’s 239 flathead?
I’ve been told that it will hammer the valve seats if I don’t.
Any truth to this?

 

For what the additive costs it's cheap insurance,I had a Caddy engine go south because of unleaded,if you ever overhaul the flatty hardened seats should be on the top of your list.