Low gear set from A999 installed into 904. Anyone experience gear noise?

Messed with the car a little more today. Have a recording but can't upload. May have to do the YouTube thing. Anyway I get the sound in all 3 forward gears so I guess it's not the low gear set as moparlvr166 pointed out. It's an odd sound almost like a generator winding down as I coast and slow down. Kind of like Grrrrrrrrrrrrrrrr. Not a whine.