ive read that the operating range is only up to 5500...at least for the stock one and the edelbrock hi flow ones...

 

5500 for a bone stock TPI is pushing it past its peak power output. Those things are completely out of breathe at 5000, probably quikest if you shift around 4800. The reason for the lack of high RPM power is simply do to excessive runner length, great for torque though.