Driver drop vs passenger drop transfer cases. If you have a passenger drop driveline you can keep your stock GM front axle, if you have a driver drop transfer case you will need a Ford solid axle (or other driver drop axle). The passenger drop NP241 was only used for 3-4 years and not all GM 4x4's got them.Any thoughts on why one would be different over the other? The technology should be the same, am i missing something ??