The smaller bolt spacing is for a 216 intake/exhaust system. You've probably got a mixmaster- - - -216 manifolds on a 235 engine. There will also be an intake port size mismatch- - - -you'll need stepped-down alignment rings when you get around to bolting the manifolds to the engine.
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!