There are a couple ways you can get the 3D down deep. One is take the harness out, cut the nose off, and thread it on a 1.5oz Hammerhead leadhead. Greg Vella showed me that trick a few years ago. I tried it and did have one gorilla bite on it but I missed the fish. The teethmarks on the bait after that bite were almost as wide as the 7.5" lure x( The only problem with this mod is that the rubber is so heavy it wants to slide off the hook so you need to use a lot of superglue to affix it, and then you have to figure out a stinger hook, or use a x-heavy rod and hope the fish eats the whole lure. Its what you might call a labor intensive mod :)

Another way would be to put an egg sinker on the line ahead of the bait or try weighting it with mojo weights. Those are marginal ideas that may or may not work out. Hard to tell on each bait if it will work until you try it.