No idea who makes this carrier because there is no name on it and it was in the car when I bought it.
Apparently there are carrier series 3, 4 and 5 now.
I have a series 3 carrier which I identified this morning by info from a 4x4 web site that shows measuring it from the ring gear mounting surface to the outside of the carrier bearing. If it measures 2.225" it's a series 3 and if it measures 2.360 it's a series 4, no idea about the 5.
Richmond 4.10 gears must be odd because the series 3 carrier should support 4.10's without a spacer.
Anyway I ordered a spacer today.
Thanks,