I am writing this email for a friend of mine. He has a 1980 Doge Power Wagon with a 6 inch suspension lift and 35's. He wants to know how effective lockers are, how they work, what type is the best for him, installation, all the details. He said he thinks his truck has Dana 44 and 60, not too sure. If anyone can answer these questions I'm sure it would be appreciated. Thanks