Thanks for answering, I was counting on you!
I think, in fact, your post answered the question that I couldn't find in the 1966 Shop manual, which I have on CD.
I think maybe re-reading my post I wasn't clear.
I have a 66 with the 20A fuse in the lighter/flasher position. The picture I put up confirms that. I think my first sentence may have confused things, as I was referencing the picture you had put up last year, of the "66" wiring harness, which reading your post, it is really a 65 box.
So, in reality, the harness I have, for what I have, the standard 66 setup, lighter, emerg flashers, the 20A in that position is correct for my car, I believe.
What page in the shop manual has the ratings for the fuses, etc. I looked yesterday and couldnt find it, but did find a drawing of a fuse block on page 15-9, which is a "typical" fuse block drawing, also most likely a leftover graphic from 65, or perhaps the Falcon or another 66 that the manual covers used the 14A in that slot?
I am pretty certain that my harness is original, so maybe we could surmise that sometime between Feb and April of 66, they maybe used up old stock of the leftover 65 harness and put in the 'newer' 20A cig/emer fuse blocks.
An interesting question-
Check out my restoration pics!