At 70,000 Km valve train becomes noisy. Dealer does gunk removal, claims noise is much less but I don't think so. Still makes a lot of noise. I've been told this is a great engine. Is that a fact??
Yes, it is a fact that it is a great engine. You just ran into a problem as any car owner eventually does. In fact most of the people who buy Crown Victoria's are very happy with them.
I guess a lot of it has to do with how your crown vic was used before you got it, generally the police cruisers run like a dream because they are maintained and babied by the police department. But if yours came from the Taxi's (most likely using propane or natural gas) then yes, as they just run them for as long as they go until they are no longer worth keeping.