Put a 235 crankshaft and rods and a set of .060" oversize Buick 215 V8 pistons in the 216. You'll have a 235 with "numbers-correct" casting numbers for the original engine. A 3/8" stroker crankshaft will make it a 258.
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!