I thought the Performer shared the same base with the RPM and that the RPMII was completely different. I hope I'm wrong because I'd love to upgrade to the RPMII by just buying the upper.
I thought that the only difference in the base was that it wasn't port matched. I could be completely wrong though.
not to steal your thread but does anyone know what the part # is for the gasket from the upper to lower intake. I havn't been able to find it yet. I have yet to find it and yes they are different!