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Does the slip calculator take my hydraulic jack place into consideration ?

A jackplate will not effect the slip calculator. The calculator merely compares theoretical top speed to your actual top speed. The issue in this situation is your theoretical top speed is only 70 mph with zero slip. That means something is wrong with one of your numbers.

post a pic of the prop. Does your stock lower have four water intake holes on each side? if so< you can plug the top two on each side with epoxy or silicone and still get good water pressure and raise the lower pretty high without a lwp cone. more pics of the boat/ motor prop would help.