How about a bent rod that caused the timing chain to break and come through the top of the valve cover..... 173400 miles on the old motor... One big change is that the new one doesnt surge all the time while running and its a lot quieter....

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1991 350SDL
1978 300D
1995 Chev Conversion Van
2001 Mazda PU
1966 Chrysler New Yorker
1994 Lincoln Town Car