[TimG]

Today, you have to ask the "engine" question different ways, all the answers must be right and then you need to check stampings, broach marks, casting dates and casting numbers. Here is what I ask.
Is it the original engine? Has it been decked? Has it been restamped?
Matching numbers does not mean it is an original, unrestamped engine. It could be the original restamped engine, or it could be a replacement engine that is stamped to look correct. I don't think people would want to pay top dollar for this type of "matching numbers" car. There is usually a way to tell a "hammered" motor, I have a pad library of different pad tracings that is always in my wallet. I carry a scope to enlarge the broach marks to see if they cross at all, they shoud be parallel and never cross each other or overlap. I have most all numbers referenced to tell what a "3" or a "9" should look like for a specific year. Do your homework and ask questions. Follow the paper trail and owner history. Past owners will rarely lie.
If you do your homework, you should be able to bust a fake.