I've seen those adapter rings, too. Probably just me but that always seemed to be a "sort of okay" approach. I've had both the VSS speedometer and the GPS type. And I can tell you there seems to have been a high degree of copying done by the folks in China here. Copying of the Speedhut products, that is. At the heart of it, the GPS speedometer is not a really complex thing. Some have opined the stepper motors used don't have enough torque, but they're only moving a light needle so I don't imagine they need much torque for that. I do understand you wanting to be deliberate about this. As I mentioned, I'm working on building a drop-in GPS unit that can be used in the AD trucks...just not quite there yet.
