It sounds like somebody at McGurk knew what he was doing. The best combination for dual carbs on a 235 would be a couple of Carter carbs for a 216. An even better choice would be a couple of carbs calibrated for an engine of around 180-200 cubic inches, if something like that could be located. Putting two of the same carbs on a 235 that were designed to perform right when only one of them was installed is about the biggest exercise in stupidity that I can think of. Doubling the venturi area and expecting to avoid flat spots and lean-out conditions when the throttle is opened quickly doesn't even make good nonsense.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!