104 octane for my 360 ?

Does it ping with more timing????
I remember talking to you before but i don't remember what cam you have.
How big is the cams duration @ 50 thousands lift, and have you done a compression test to see how moch cylinder pressure you have.

Knowing how much cylinder pressure you have is the key for what fuel to use.
What is the timing is set at, and does it ping under load for that setting on pump gas. (wot)