Depending on what kind of 4bbl's. Late 50's/early 60's stock Chevy 283's with 2x4 Carter WCFB's aren't a little much. They're only about 370cfm each.
3x2 are a lot cheaper to buy and set up than a 2x4 ! I will be running a 3x2 with Holley 94's on my 292 that I am building !
I ran 3 97s on a 312 when I was a kid. it ran good, didn't care about the look so much it was a Saturday Night Special. These days I'm leaning toward 2 4s but its probably just a phase I'm going through.