The only way it would really be able to take anything but the highest octane is to run a huge cam. But that will also make it not streetable.
Find out what it has for pistons, maybe they can be cut down to lower the comp.
Maybe the head could be swapped to also lower the compression.
Another idea is to use a copper head gasket with a standard head gasket, this will also lower the comp. Flatout gaskets are good to use here. They have a rubber coating and are made to run with a oringed head gasket. Tom
