Yep, LRP almost all gone now.
Regular unleaded is absolute crap. Most performance cars should be OK an just premium, which is about 96 octane (same as LRP), but if it still pings with the timing where you like it, then the 98 octane fuels should fix it (BP ultimate, Shell Optimax etc).
If you take the heads off and drop them into the head shop its not too expensive. Shop around for prices!!!!!
Why not go for a full port and polish while they're off