Gary, I failed to mention that you really need a spacer on the intake to cover up the voids in the carburetor pad, and it would be even better if you had the four holes blended in a radius to help prevent turbulence. The radius would be facing the super sucker. I have tried that with up to three inches of spacers. An open plenum works best, but the high riser 4V is a dual plane, and needs some help with that carb pad. Joe-JDC