OK I will post a full thread on this when I get a chance b/c it has made a difference in my gripping abilities:
The kind of strength that carries over best is pinching strength to work this start with two 10 pound plates and hold them between your thumb and index fingers. Do this until failure and when you can hold it for 30 seconds +move up in weight. There are a couple of things you can do with a kettle bell as well.
Another aspect that will improve your grip strength right away is to grip everything you lift as tight as you can throughout the lift. When you do speed deadlifts, drop down and grap the bar as hard as you can and as FAST as you can, then pull FAST.
The same goes for olympic pulls. Drop and pull as fast as you can for a few sets at the end of each workout.
The goal is to make the thumb to fingers squeeze and hold strength better. By exercising your fingers specifically you will develop better weightlifting grip...that is all I can think of for now