You can either widen the thrust face on the 235 crankshaft, or narrow the #3 casting web and main cap in the block to accept a 235 main bearing. If you whittle on the block, you can also use the 56-63 235 main bearing shells that are much more available (and less expensive). I'm building a machining fixture to do that, using my Van Norman cylinder boring bar as a driver. 215 Buick standard bore pistons are the same size as 216 pistons. 60 over gives you 235 "standard" bore and stroke- - - - -in a 216 block.
Jerry
