Currently, I have two 235 crankshafts modified to fit 216 blocks. All that's needed is to widen the #3 main bearing thrust faces to fit the 216 main bearing, being sure to remove the same amount of metal from the front and rear faces to keep the timing gears aligned properly. If the original connecting rods are used, the pistons will stick out of the top of the block due to the increased stroke. A 292 six connecting rod is the right length, but it has the wrong size bearing, so the crankshaft rod journals would have to be reground to 2.100" to accept the 292 rod bearing. Then you'll need to put bushings in the top of the rods to fit the smaller dfiameter 216 wrist pins, and fabricate thrust buttons from aluminum or teflon to keep the wrist pins centered in the cylinders. The rods are too narrow for the crankshaft journals, so weld thrust washers onto both sides of the rod caps to keep the rods centered on the oil holes in the crankshaft. Recondition the rods to eliminate any misalignment welding the spacers created. You might as well go ahead and bore the 216 cylinders 1/16" oversize and use the 235 aluminum pistons while you're at it. Now you have a 235 engine in a 216 block.
Now, you're going to need more oil volume to keep the rods oiled. I make an adapter bracket to run a pump for a 250 six, along with a shortened drive shaft for a big block V8 oil pump to connect the distributor shaft to the pump. The adapter has bronze bushings to keep the drive shaft centered. Then remove the spray oiler plumbing from the oil pan, or find a pan for an early 235 with a straight rail on the passenger's side. Then plumb new tubing to the oil pickup screen and the oil galleries in the block. Plug off the oil port that used to supply the spray oilers.
If you're still interested, I'll share a way to make that 216 engine a 247 by using a different connecting rod and offsett grinding the 235 crankshaft. Bring money- - - -lots of it!
Jerry
