Sounds like you tired to use the same carrier your tall gears came with? The 2.45 carrier moved the ring gear over, but the pinion location didn't change. If you tried to bolt the 3.55 gears to that carrier, it would make sense that the gear might rub the case, but worse yet, even if it did spin it probably wouldn't ever get the back lash in spec anyways.
I wouldn't be that surprised if some of the confusion comes from people trying to swap gears using the wrong carrier, as there is definitely different ones of those. I could see buying a sure grip carrier from some guy at a swap meet that swore it came with 3.55 gears while it in fact was one for 2.45 gears. That gets plugged into a housing and won't work, so the assumption is that the housing is wrong and there must be different housings. Just a theory.
