Take anything that's posted on that website with a big grain of salt. Lots of misinformation there. A Carter YF for a 258 cubic inch AMC six will bolt onto the 261 intake, and it will be calibrated very close to correctly for the displacement of the engine.. It's also got a slotted throttle body that will fit either stud spacing. Rochester carbs make pretty good paperweights, but if they've had any gasoline in them lately they get pretty stinky.
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!