I have a 425 nailhead that was built for torque. It has Tom Telesco pistons, 1959 401 heads, a torque producing cam, a switch pitch turbo 400 transmission and 3.o8 rear end gears. I am using a Edelbrock AVS2 800 CFM carburetor with a 1959 401 4barrel intake manifold. It runs well and I can spin one tire with ease and gets about 12 MPG. Now the question. Going through some stuff I found a Quadrajet manifold for a nailhead. My Edelbrock carb has the same bolt pattern as the Quadrajet intake manifold. I have read about the Quadrajet manifolds making good power. Installing my Edelbrock AVS2 on the Quadrajet manifold would require a spacer. Would I gain anything with this conversion. I have at least 12 inches between carburetor and bottom of hood.