Engine Ticking Solved

A few days ago it put up the following post:

I have a 66 convertible with a 289 engine and a C4 transmission. There is this annoying
tick-tick-tick from the engine. You don't here it when driving with the top down, but you
do when it is up. Of course it is quite obvious with the hood open. I still have the 'soft'
valve seats, and I use lead substitute every other tank or so. Any Ideas on how to get
this to go away. A mechanic friend of mine said to put Miracle Oil in for a few weeks prior
to an oil change. Is this a good idea? Will it Help?

Thanks in advance for any help you can give me.

It has been solved, and here is what is was:

I took the car fora drive to the local service station (the kind that sell both gas and fix cars) to buy a newspaper. I asked the owner, who is a fan of vintage cars to take a listen. He immediately said it was an exhaust leak. I popped the hood, he closed his eyes and put his ear by the engine. He said it was coming from a spark plug. He popped off the wire, and sure enough, it was so loose, he could tighten it with his hand. He offered to get his tools, but I told him I would do it at home. Once I tightened it, the ticking was gone. There nothing likea good ear. Best 50 cents I ever spent.