the only way smoke could come out around a plug is if it's loose or there's a major crack there - or if a 216, maybe the side cover is loose and some oil is leaking there and burning off? .... for the "knock", it would be a good idea to have a mechanic listen to it, could be a problem or just need a valve adjust .... if the engine sat unused for 30 years I wouldn't have much faith in it - might want to arrange to have a tow truck in the wedding parade
Bill
