Best 273 and 318 builds (NO 360's please)

Use a smaller cam. Something like the XS268S solid but run 1.6 arms on it. I'd go with 1.88/1.65 valves and blend the bowls after the 5 angle job. For a carb I'd use the 570SA and I' use it on the Performer 318/360(small port) that should be gasket matched with the heads. Comparing apples to apples the 770 street avenger is equal to a 920ish cfm 4150. Way too large, especially with that 3.55 gearing.