I know this has been touched on before but anyone have any further testing??

Mine is 1-1 1/2" higher than from the factory. I have not measured it yet to be exact. I remember reading that it should be kept lower for more bow lift but have spoke to others saying try higher.

Any thoughts??

Lots and Lots of Talk on this subject.
Krackmeup has done the most recent testing, so get with him for results.
I believe that the "standard" X- dim for a Y2K is around 18-1/2" which would put the prop shaft about 4-1/2" below the bottom.
If your boat was rigged with the prop shaft higher than the "standard", your boat will likely benefit from adding a spacer.

Pat's right, I have only about 3 hours on my newly added 1" spacer and the boat is MUCH better. JC and Rick have done a lot of testing and believe it is where it should be (according to JC), but we all know it needs a bit more bow lift. Since I have added the spacer I get less blow out (still owe BBlades a call to optimize from my 26P non-labbed Bravo 1 prop) and the boat just feels better, and turns quicker for sure. I posted all this, not sure where anymore, but do a search to see if you can find the data, or call me sometime - PM me for a phone number if you like!

Keith

Just found it - see the Hydromotive P5 post

I believe my prop shaft is 3.5"s below the keel.