Avgas 100 LL
Avgas 100/130
Avgas 115/145
All are leaded and will give a kick up in octane when that lead hits the unleaded
gasoline. The percentage of avgas should be kept low.
I would not go over 25% Avgas in Super Unleaded Gasoline.
Try smaller amounts first to see if the octane level of your blend
will work for you. No need in throwing high dollar avgas in your
tank if you can get by with less.

Avgas 80/87
Don't bother with this one, as it has little or no lead in it.