Hey John, the mods were done 1 at a time. Your boat would be the 2nd generation hull with the smaller steps, and the chines are not dropped.
The pics below shows what you would do to drop the chines.
Dropping the chines is the biggest thing for stability below 40. Essentially by dropping the chines, you are giving the back section of the boat less deadrise which helps stability. Also, you are giving it more transom lift, which helps the boat run at a little bit better angle of attack, and it might give you a few more mph up top as well as help you get out of the hole a bit better.
I don't know the exact specs on the 280s vs 380's..... In the pics it looks like you have 280's, but I didn't think they were 18" long. If you could get a better top pic view of the tabs, I or somebody else would be able to tell you.