A cast iron CJ intake is 6.000" high, PI is 6.375", and Victor is 6.500". I have used the PI with ram air hood and short spacer. I have also milled the Victor for use with Shaker hood, so you have a choice if you so desire. I don't think there would be anything to be gained by using a cleveland 2V RPM air gap in the spacer over a FE Performer RPM, or BT, milled Victor. JMO, but information for thought. Joe-JDC