You may have to run a spacer with the air gap, i modified a 71 340 intake haven't run it yet, but i did mill the divider and slightly enlarge the plenum area, Hit all the turns trying to radius them to a nice rounded turn, then gasket matched the ports as far in as i could get with a 6" bit, also got rid of some of the lumps on the roof of the ports. Then made a larger oil splash shield for the bottom of the intake. Have about 20 hours in it and you would be surprised how much metal was removed.