Those Keihins are sort of a downsized version of the Stromberg carb used on some of the British sports cars back in the 1970's like the Triumph Spitfire. 3 of them on a 235 or 261 Chevy six should have approximately the right CFM rating, and the mixture is adjustable with jets and metering rods.
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!