Here is the drawing of the the block, showing the factory spacers.
You'll note that the tolerance between the caps and the block, is .3725 - 3775 and you only have 3 spacer widths (red, blue & yellow). They tell you what spacer to use for the particular gap range of .0017-.00165. So, the spacers are just one size and that size, maybe .00085 larger than the small end of the spec i.e. the blue maybe .375 thick., the red, .3767, Yellow, .3733.
If that's the case, Ford is allowing .00085 interference and .00085 clearance for the min/max fit.
It would be good, if we could get the specs for the part numbers of the 3 size spacers.
I'll try to measure my spacers tomorrow and see what I have. Who ever rebuilt it last, did not put them in as marked but, they were all tight, with the exception that one wasn't as tight as the others.