HELP! I need info on what series my 10 bolt posi is!

[1774btcrew]

I have been doing a ton of research on these carriers. I have a customer that wants to purchase this from me but I want to verify that it will work for him. I went to this website: http://www.nastyz28.com/forum/archiv...p/t-17931.html and it says that a 3 series carrier will hold 2.73 and numerically higher gears(3.08, 3.42, 3.73 and into the 4s) 2 series holds 2.56 and numerically smaller. Is this correct? I have 2two 10 bolt posi 8.5 carriers. One has 2.56 gears and one has 2.73. Most of the information I have found on other sites says nastyZ28.com has the right info. I have a friend that sells a lot of carriers to a rear end shop and he says all that matters if they are cast with a 6 or an 8 . He says the 8s are 3 series and the 6 or 9 depending on how you look at it are 2 series. I need some definitive info as this will be shipped and I don't want an unhappy customer. I would appreciate any info you guys can give me.