Memories fade, but I tend to remember the loudness of concerts by the amount of days afterwards where my ears continued to ring. I also have to say that volume level varied a lot as to where I was sitting...or standing.
Anyway --
Led Zeppelin at the Shrine Exposition Hall (or was it the Rose Palace?).
Blind Faith at the same locale.
Whole bunches of bands at the Whiskey. They liked it loud at that joint.