I can run regular 85 octane gas since my TRD SC is only at 5 - 7 pounds of boost. I commonly go from 4,000 to 12,000 feet on the different trips that I make. I can't speak how it will work at lower elevation. IIRC the kit said that you could run regular gas. Regular gas at sea level is 87 octane. It is higher since you have so much more air to breathe.
If you run an intercooler or are water injected like CDAN you can still run regular gas with reasonable (<8 lbs.) of boost.
Do you have an 93 or 94 cruiser with a super charger? just bought one and need some advice with the install.
Kevin