I bought a 292 Y-block from an older local gentleman. He has spent the last 22 years living in a warehouse, and doing nothing but "playing with cars", as he put it. He has quite the collection of Ford products, with the FE motor being his engine of choice.
Some people will surprise you with what they have. I haven't come across any cammers yet, but I live in NASCAR country where guys like to race, and some have stuff that can surprise you. A lot of cycled-out NASCAR team stuff has a way of making it down the friend chain and into someone's project. That's kind of how I learned about the mystery motors. A guy had a part of one hanging in his shop.