That's a good idea actually...a 'Wanted' ad instead of just searching for Sale ads.... FB marketplace has a lot of items popping up regularly, and craigslist is about the only main one I use. I search it nearly daily. But so many people sell stuff with limited details that I have to pull out of them, and I have actually gotten burned on engines before for other projects...
I mainly just wanted a running bottom end I can toss my manifold and carb on and go.. for all the efforts I may just bite the bullet and get a new/reman'd crate motor with a warranty... but that's a good tip, Ill see about putting out a wanted ad