Let's see now,216 has a 3-1/2" bore,3-3/4" stroke. 235 has a 3-9/16" bore,3-15/16" stroke.Could be a 235 crank,but would require special pistons because of longer stroke. Some oldtime nanufacturer used to make them,Mcgurk or Nicson I think. I have a 1952 J.C. Whitney catalog where you can purchase a 216 shortblock with the 235 crank. But I highly doubt that's what you have. Someone probably converted the babbit rods to inserts at a previous rebuild. If done properly they're fine.
As for the bolt holes on the balancer,they're 3/8"-18 or course thread.
I like the factory shop manual best.
