You can waste billions of electrons asking questions, and there's probably a 75/25% chance that you'll get the wrong answers. Nothing beats taking things apart and confirming what's actually there. Hydraulic lifter blocks have a BIG oil gallery drilled from front to rear through all the lifter bores, and passages from the oil pump big enough to keep them filled. Most, if not all of the late model 235 blocks had the lifter oil gallery drilled, even if they had a solid lifter (truck) camshaft from the factory. The head bolt with the 1/16" orfice drilled through it was only needed when a particular mismatch between early and late blocks and heads were used. There's no telling what has been done to a stovebolt engine since it was new, so chasing part numbers might be a fun pastime, but there's no guarantee whatsoever that a 60+ year old serial number means anything at all!
Jerry
