What are your fuel limits/availability? With a vert (400+ weight) I suggest a taller gear (3.23-3.55)
Keep the 670 heads, machine the seats down to accept a 1.71 installed height, keep the CR the same with 104-108 octane and go with an 068 regrind from Comp Cams.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
