That looks suspiciously like the OEM Corvette manifold. Fitting SU's would probably be less expensive than acquiring the original Carter carbs and they might work better due to the air valve setup.
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!