I have a driveshaft signal and a new EFI product to add to the list. I tooled up a stainless steel bracket that bolts to the Dana 60 pinion snubber mount and holds a Holley flying magnet sensor.

One odd thing is the Holley instructions for the 554-125 sensor have been updated and now say to not use that sensor as a driveshaft sensor. I wonder why they did that? If the driveshaft has a flying magnet on it then it seems like it would work just fine.