David,
Seriously, the booster I used way back in the 70's actually had lead in it, but as I said, my 356 preferred the real thing.
My last time on One Lap of America, we ran out west and knowing that our 400 HP small block Chevy wouldn't like the gasahol out there, we took several cans of Moroso booster with us. Of course, it no longer has lead in it. After using it for about three tankfulls, we concluded that while it didn't hurt anything, but there was no measurable improvement over what was coming out of the pumps....The small block didn't like it either way.
Later on I read a technical analysis of what was in it and the author concluded that the minimal gain in octane wasn't worth the cost and/or trouble of carrying the stuff around and remembering to pour it in the tank.
Hope this helps.