318 Four Barrel Intake
Using a good 500 cfm AFB ,tuned properly, you'll get better mileage with the 4 barrel, keeping your foot out of the 4 barrel's. I don't have any info on that 4 barrel intake you quoted, but stay with a small port ,dual plane intake to maintain good port velocity and fuel atomization. Stay away from the large port 340/360 intakes.
That's just my $0.02 CDN....