Airplane fuel would have the octane rating you need, but won't have any lead in it, so you'll have to go to hardened seats, anyway. Octane boost has the same effect, but might have more stuff added to it to help lubricate the exhaust valve seat.

If you're thinking of putting these heads on a 455, then you'll have to go whole hog on the head work, run a huge cam and some headers, and generally hate driving it down to the Piggly-Wiggly for a 6-pack. Unless the Piggly-Wiggly happens to be exactly 1320 feet away ....