I finally was able to run my boat with new tunnel tab. Good results all around. At cruise speed 60-70mph with tab down no porpise at all. Added bonus at top speed with 4 blade props gained about 2mph. Could feel the entire boat lift. With 3blade did not see any speed gain. I only ran about 1hr , with a little more time I may learn some more. One tip When I put tab full down to get on plane The boat was bow steering so much I almost crashed.

thnx for info mmwalters.
i think i will try mine in two weeks.
will post results


*Actually i am expecting more top speed gain. like 4-5 mph.Cause my boat is quite heavy,specially back side of it.do you think its possible?