Can anyone give me information of modifying my hull for better performance?

I have a 20'5" Key Largo which has the hull copied from the old Sea Craft of the same length -- the variable deadrise hull. If you're not familiar with the hull, you may not be able to help.
I am very happy with the performance characteristics of this hull, except for one. It exhibits what I first thought was a bow-light/stern heavy condition (200 hp FICHT on transom), despite having a fin on the lower unit, meaning that going into any type of wave (down-sea or up), the bow would come up high out of the water while the stern would not budge. So when I bought it used, I added 12" Lenco trim tabs, leaving the fin on. This helped somewhat, but now I know that it is not bow light, but rather, the lifting strakes on the bow only extend to the beginning of the first deadrise change, thus providing tremendous lift in the bow, but not the stern. Altering wieght distribution has no effect. In 2-3 footers or more, I find that I still have to deploy the tabs full down and trim the engine down all the way to minimize this, and then I am just plowing through the waves like a tank, over-working the engine and destroying fuel economy and performance. The upside is, you can not make this boat pound.

I am assuming that the best option would be to try to give more lift to the stern....Does anyone have any experience modifying their hull, such as installing lifting strakes (in my case, from about amidships to the stern)? I would appreciate anyone giving me information or letting me know where I can find the information that I am looking for.

 

Depends what it's built from. if it's grp, be careful, if it's wood, you're ok as long as you seal any modification well. I don't know if you could devise some temporary way of fitting things to the hull, but I would be inclined to try extending the strakes at first, if that sorts it do it permanently. DO NOT screw anything into the hull without sealing it with either epoxy (or gelcoat) (preferable but permanent, squeeze in the epoxy, then screw in) or (at a pinch) yacht varnish for wood (except that not a lot sticks to it afterwards)

Tim B.