Trivia #33 - What % of 1963 Cadillacs Came with Limited Slip (Posi) Differential Rear End

It has been way too long since we posted any trivia (and gave out a cigar), so here is one I thought I might have posted but do not see it:
What % of 1963 Cadillacs came with the optional "Controlled Differential" rear end? (What most of us call Limited Slip or Posi-traction)?

Need to get it within 5%. 

ps. The 1964 Cadillacs saw a very slight uptick. 

So, who will get the cigar!

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OK. No guesses on what % had posi rear end. I will help you out... it was less than 25% ... and lets say anyone that gets within 5% get's cigar!

ps. I know I mentioned this before but I am getting these details stats from the Wards Automotive Yearbook.
They came came out each year and had tons of info on automobile production.

Here is the AI generated summary:
"The Ward's Automotive Yearbook was a prestigious annual hardcover publication by WardsAuto (an old industry media company) that provided in-depth statistics, news, and analysis on the global auto industry, covering vehicle production, sales, technology, and market trends, serving as a vital resource for manufacturers, suppliers, and dealers until its publication format evolved with digital shifts." 

I’ll have a crack and say 18%

I would have thought it to be more than 35%

Phil gets within 5% so ding, ding, ding --> We have a Winner! --> and  he get's a cigar!

The actual % of posi rear ends for 1963 model year was 13.2%.  That  number would increase slightly to 15.4% in 1964.  My guess is there would have been more cars delivered with this option in the northern states than in the south.  I have of course never seen that type of data breakdown but bet Cadillac kept it at the time. I sort of remember pulling in 5 or 6 posi equipped cars out of a total of 60 + 5 other driver cars, so my % is expectedly lower than the overall average with me living in the south and my sourced cars tending to come from the south. 

So ... Phil ... HAVE A CIGAR!!!!

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