Steve, my IPC for the Class IIIs shows the same part number, SBA395870300 for a "Control Unit" with an arrow pointing to exactly what is called a glow plug timer or glow plug timer relay in other places in my Users Manual and Repair Manual. (Gosh! I wish they'd use the same nomenclature.)
Anyhow, this illustration shows that the control unit has an "ear" on it for attachment with a screw after it is plugged into the socket. The other relays do not show that ear attached. They are just simple plug-in relays.
The part numbers for the other relays are:
Glow Plug Power: 86529089 (30 amps)
Glow Plug Light: 86509590 (20 amp)
I think the SBA... numbers are sometimes temporary numbers. I know some of the filters on my tractor had SBA numbers that have changed to permanent numbers starting with 8xx... . It's possible that the number RickB gave you is the permanent number for the controller. I just don't know why another dealer wouldn't have the same information. /forums/images/graemlins/confused.gif