PapaLarry....Here is great site to tell you about pruning Crape Myrtles, also has some good illustrations.
How To Prune A Crape Myrtle
We actually cut ours back more severely this year because I don't like the long "leggy" look of the trunks with just the tops having leaves. Prefer more leaves and less trunk. I was concerned, but not only did it come back, but it came back fuller and is still growing! My hubby is just amazed how they come back. We cut ours back in March. We even have a baby one that has sprouted beside the big one. It came up last summer and this year is about 2 feet tall so far. Waiting for the trunks to get a bit larger to transplant.
If you have Japanese beetles down there (we are still in SC), I strongly recommend using a systemic pesticide on them because Crape Myrtles are one of the beetles fav food. The one year I didn't use it you could actually hear them munching on the leaves as you walked past, and the tree seemed to "move" with them. It was disgusting and they would fall out of the tree all over the ground and all over you if you were standing near it. I use the Bayer Advanced granules and put it on in the winter.