What Is A Formula 'S' Package 'Year to Year'

Yes, there were a few Tests done on the BB Barracuda in 66. I also know they were selling them in December. It appears they weren't produced/delivered to the GP until March - April though. The earliest SPD I have is Feb 27th and all the rest from March 20. I am open the believe differently I just don't see it in the documentation I have been able to gather.

I have heard the gear options outside of the 2.23's were not recommended as well as the 16:1 fast ratio steering.