Thanks for the leads Kevin. I recently purchased a would-be 428 from a guy who's deceased brother was a Ford collector. It was a 390. It was also full of rust like it had water in the cylinders for a couple decades. There was nothing good about it. It was $100 for the engine, so I took the gamble. There were a couple sets of 429-460 heads and closed chamber 4v Cleveland heads I bought for really cheap along with a few other items, So, the 100 wasn't a big loss.
I use a craigslist search called zoomthelist.com. I am surprised neither of these two that you listed had come up for me. If someone is selling one of these out of his garage at home, chances are he is not going to palletize the whole thing and bring it to a commercial address to be picked up by truck freight. But, ya never know until you ask.
I sent an e-mail to DMC about buying a block and crank. He has top oiler 427 blocks listed at the same price as a 428 block. If that is the case, then why make it correct when you can make it better than correct with a 427 block and a 428 crank, or a 4.25" stroker crank? The big wagon could always use some extra cubes.