[Dafni]

I use alu cups on both my BL revos, one has alu housings too. Not sure about the brand anymore to tell you the truth. Have different brands, but one cups are 3racing, probably.
I can tell you this, they are okay, work fine and all, but since they are still 2 spider diffs, the spider-shaft eats his way into the alu something wicked. It takes some time, true, but after 1 year of running this small shaft was the very devil to remove.
Just a thought. Would still buy them again, though. To bridge the time until someone comes up with a proper 8th scale diff conversion.

DAF