You mean 94 ocatane, right?
Actually, the highest I usually see is 93 and in some rural or beach counties only 92.
The highest boost I've heard of on a JRSC is a 12 psi pulley. There might have been someone experimenting with a custom 15 psi setup but I am not sure. The problem with running higher boost on a JRSC seems to be that because there is no way to intercool or aftercool the intake charge (other than water/alcohol injection) it tends to get really hot and loses efficiency after a point.