Two 94's or 97's are all a stock engine will handle. Thats 165 or 150 CFM per carb for a total of 330 or 300 respectively. If you go to a 4 bbl, the Holley 390 is all you want up there.

More that that is wasted fuel and poor performance. You just can't jet them down enough. But at wide open throttle they perform well - it's just the around town, streetablity that suffers.

Go to two carbs and you have to run them at the same time - you can't use progressive linkage or you'll burn valves.

Options: block off the middle carb and run two OR run all three with the center one as your primary carb and the front and rear to come in only at 3/4 throttle. It'll take some fiddling and will probably run rich. But they look so sweet with three duces!