What octane does 9:1 compression need?

Why would they go 9:1 on a supercharged engine? What size pulleys are on the chargers? Also, 9:1 static compression means nothing with a blower on it, if it is 9:1 I highly doubt you are running more than 4psi boost.

89-91octane. You have EFI, so check knock counts when you first use 89.

Almost positive his engines are NA.

Yes engines are NA .......575's efi's old skool arizona speed & marine