I don't recall replacing them when I did the cams in 2007. I'm not sure if I
simply didn't know about them back then, or if I was told that they didn't require replacement. Now I suppose I could have simply screwed up and failed to put the front washer on 5 years ago when attaching the crank pulley, but in order to get to the rear washer, you have to remove the oil pump sprocket and then slide it and the crank sprocket off the nose of the crank as a unit (there is virtually no slack on that chain even when the tensioner is removed). I am absolutely positive I didn't touch the oil pump 5 years ago, and given there is no reason to remove the crank sprocket unless you're removing the crank or replacing the rear washer, I can't imagine I would have taken it off, removed the old washer, and then put it back together wihout a new one. This tells me that these washers were never on my engine.
As to why they were never there, I suppose it's down to the engine's
history. It was purchased from Kansas Racing Products who manufactured alloy racing blocks for Ford who in turn gave them sweetheart deals on excess engines. I was told these engines become available for a variety of reasons: over production, pulled from the line for Quality Assurance testing, or simply for the engineers to look at and measure. Because none of these engines are considered “new” Ford can’t resell them as crate engines, so they are stuck with two options: destroy them or allow their “friends” such as KRP to resell them at deep discounts to their own customer base. When the engine arrived, the coil pack mount was missing a corner, but other than that it looked brand new and had never been fired. Perhaps there was an issue with the washers on the assembly line that was dioscovered after the engine was assembled, and it was deemed cheaper to sell it (and possibly others) as an excess engine, rather than repair it.
Between this and the cam bolt issue described below, I really dodged a