It's also possible to use GMC 228/248/270 connecting rods narrowed to fit the 235 crankshaft. They're 7" long, and will allow the 215 Buick/Olds V8 pistons to be fitted to the 216 block. Flathead Ford 85 HP V8 rods are also 7" long, but they require some more sophisticated machining. The 235 crankshaft can be stroked an extra 3/8" by using 7" rods, a piston for a Japanese Diesel forklift, and rod bearings for a CJ-3 Jeep 4 cylinder engine. That makes the stroke 4 5/16". (Longer than a GMC 302!) A 216 bored .060" oversize with a 4 5/16" stroke comes out to 258 cubic inches! That full circle oil seal is a Timken #417210, or the equivalent from SKF or National- - - -3 7/8" inside diameter, 4 7/8" OD and 3/8" thick. It has enough "stretch" on the lip (up to .015") to accommodate a "speedy-sleeve" on the crankshaft hub.
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!