[ds1]

Block casting date is under the one motor mount. I would sell it as is. Taking it to your machine shop is not always good for the next guy. My shop doesn't always like parts I bring them because it is not how "they" would do it. The 425 is a sequence number and the main caps will have that number on them if they are original. Those engines were hard to machine when new. From sitting all these years it will be brittle from not being heat cycled. At most have it magnefluxrd for cracks with a receipt to assure the prospective buyer the block is ok. That's my thoughts