Gary,
I've found, for me, achieving depth with a crank is a combination of lip length, width, and line tie point.
I have my prototype lure in the garage drying right now. As soon as it's dry, I'll post a picture in the gallery.
I made the lure body 3" long, 1 3/8" tall and 3/4" thick, so it would have plenty of buoyant material toward the tail. I made the lip wide for most of it's length, and only tapered it back toward the lure body at the very back.
The blank, when carved and with the lip attached, weighed 27 grams, and I had to add 9 grams of ballast to get it to hang down at the angle I wanted, so it would dive immediately.
I'm hoping it dives deep, and is snagless.
I'm taking it for a swim tomorrow. Fingers crossed.