Hi Oscar,
I did not have much luck with the extended cav plate, however I did have luck with the trim tabs, Billy R. clued me in on that, I extended the sponson bottoms out the back, during a rebuild from a huge blowoff I had, about 1/4 inch, Bill cut his back to about 1/8 inch, this did work. You could make up a small set to fit your hull out of aluminum I would think. Use double sided tape to hold them on for testing till you deceided if ya liked them or not.
Gene ;D