Those look like the Fel-Pro ones for cast iron manifolds. I have a pile of them as they are what comes in the whole engine gasket kits.
They seal great on manifolds that are flat, but do not work on headers very well.
I have had good luck with the factory Hooker. MR.Gasket and some other white one's. The Fel-Pro ones were fine. The Edlebrock worked well too.
Clean and Flat is key and most will work fine.
In fact that I use the white ones to mark cast iron manifolds i port.
