About a week ago I hear a knocking that sounded like a "bolt in the dryer", just getting bounced around, coming from the engine. It sounded like it was up on top of the engine. Then it disappeared.
Got the same noise back again so I took out the plugs. Number five cylinder plug was smashed. The porcelain was completely gone. Electrode bent over. I was replacing the carb and had it off several times along with adjusting the carb and timing. Did I drop something in the intake? Would anything else cause this to happen? Looking at pulling the head and try to find something along with any damage I am guessing is the only thing to do.
Also the engine has had a constant miss at idle and high end. Just the smashed plug??? Looking for opinions.

As far as dropping foreign objets into the intake, only you would know if any pieces were missing after you replaced the carb. Check the dip stick to see if there is any evidence of coolant in there. It is possible to crack a head if solid object was encountered. I would rotate the engine to brng #5 near TDC and probe the cylinder with a flexible magnet. You may get lucky and snag whatever is in there. Check the rest of the cylinders as well. Install an new plug and fire it up. If it is still missing, do a compression and a leak down test on #5 at least. That will confirm any damage. While you are doing the leak down test, listen for air leakage. If it is leaking through the intake manifold, it may have damaged an intake valve. If it is leaaking out the exhaust, it may be an exhaust valve. If the leaking is audible through the oil filler hole, you may have piston damage. Understand that the noise may stem from any one of these sources, a combination of them or none of the above. Of course pulling the head is an option but I would try the previously stated tests first. Good luck.

Check with one of your local mechanics to see if they have a flexible scope. They would be able to see inside the cylinder without pulling the head. Possible you might be able to borrow one of these from a parts store but I doubt they have one to loan. Good luck.

Thanks for the reply. Tried to put a magnet in the cylinder and could not pull anything. Put a small hose on a vacuum cleaner got nothing. If whatever it is would it have to be small enough to get past the intake valve? What clearance is that? I tried looking for a borescope and can not find one to rent. When I turned the engine off I had a lot of fumes come out the carb. Would that tell me something... Maybe the object is stuck in the intake valve now?
Thanks

I tried the magnet and the scope and could not find anything. I pulled the head off and found to small pieces of unidentifiable metal parts in the cylinder. Put the head back on and now it has a knock in the engine coming from the piston area not the head. Damage to the piston, rod or crank shaft? Time to pull the engine? My question is while the engine is out do I have the opportunity to " take it up a notch". Rebuild the engine for more horse power? I would like to keep it stock looking. Anyone have pro and cons about rebuilding the engine for more horse power? What could I do to the engine for more horse power? How much would the transmission and rear end handle? Or best to keep it stock.

Mojoe, it would seem that you have more significant internal damage. It is really not possible to diagnose what that may be in this forum given the limited information available. There are just too many possibilities. We could speculate about this and that and never actually hit on the real problem. Regarding what to do next, that is entirely up to you and your wallet. If you want to keep your 'bird original and correct, then the original 429 can be rebuilt and fortified with a more aggressive cam, compression, etc. If originality is not a consideration, you can bolt in a 460 or derivative. It's all your call. JMO