There is one surefire way to identify a 235 engine block, regardless of which casting number it wears- - - - -ALL 235s, both spray oilers and the 54-up full pressure engines, are 1/8" taller from the oil pan rail to the cylinder head surface, that any 216, regardless of casting number. A 261 is the same height as a 235, since both engines run the same stroke crankshaft. That's how Chevy compensated for the extra stroke of the 235 crankshaft while using the same connecting rods and compression height of the pistons. I don't have exact dimensions at the moment, but I'll edit this post tomorrow once I get out to the shop and measure a couple of stripped-down blocks I'm working on. That dimension can be checked easily at the passenger's side front of the engine with nothing but a tape measure.
Jerry
