You shouldn't need the spacer on your 2006 model.
The spacer is to compensate for the shorter early push rods. Your pushrod could also have an "anti-rotation" pin which would certainly confirm it is the later longer type.
It wouldn't work at all with a short pushrod if the spacer was not present.
I'm curious as to what you mean by "lightly re-face the plates" and how you went about that.
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