Quote:

The '66 Plymouth book is very explicit.



You beat me to the punch in posting that excerpt from the factory literature.
Yours is a little hard to read so excuse me if I make it more readable to the unconvinced but it needs to be driven home:

1965:



1966:



I repeat my original position: It was a 99.999% probability it was dealer installed unless you produce for me a build sheet that shows otherwise.

Now, for all you guys who foolishly INSIST that they have a 1974 440 with a steel crank FROM THE FACTORY....