i think a 600 cfm carb would flow fine, i've got a 71 302 in one of my 60 galaxie convertables, complete stock engine, never been rebuilt has about 70,000 original miles on it and my carb went ou so i thru a 2bbl to 4bbl adapter plate on it and an eddy 600 and it runs beautiful, not rich not lean, and it launches hard when the secondaries kick in