[Jeff Lee]

To answer the basic question, yes...you can run any year block as long as it's the same family. The original size of the block (262, 265, 283, 327, 350) is of no concern to tech. Just bore / stroke and technically lifter bore diameter and deck height (which is primarily dictated by the NHRA spec stroke, rod length and compression height and deck clearance).
That is why you see 454 blocks sleeved down to a 396 bore. It's all good.
And while I have never raced a class car with an aftermarket block, I would if one were available. There are MANY advantages as mentioned below. The cost is negligible compared to what you get.