Brion
thanks so much for the explanation, it is very much appreciated. I have been struggling with this problem for years. It takes everything just to keep the mast straight and without any reverse bend in the mast.
So, I'm assuming that any play with the spreader rake is not good. The spreaders should be rigid to the base/mast? Catalina has improved the design of the base over the years, I might need to reach out to them and see if I can upgrade the spreader base.
I attached a line drawing of the Capri. you will notice that the chainplates are aft of the mast and she was designed with only one set of lowers.
In reference to the numbers (also see sketch), I follow the tuning recommendations from Catalina and check all of my numbers with a loos gauge.
Cheers
Stephen