Like said before the 9 bolt will last till you get traction. You also will spend big$$$ on a gear change. Miles at 9bolt.com can get diff. ratios but he's not messing with 9bolt parts much anymore.
Other companies carry gears but only 370's. Also if you have a 277,308 ratio your going to need a series 3 carrier which again = big money.They don't make a spacer ring like they do for 10 bolts to change from a series 2 to series 3 carrier.Personally I like the 9 bolts but I'm just letting you know what your in for.

 

www.ringpinion.com sells 9 bolt gears and rebuilt kits. the 9 bolt is tough, dont under estimate it. i hear those yukon gears are superb. guys who use those wont use anything else. its a private company so you might not have heard of them, i havent untilla few month back. 9 bolt parts are kinda pricy, but its worth it. better then spending big money on over kill rears

 

 

i've got 323's so i shouldnt have to get another carrier. i guess i'll just get gears and see how it goes. thnks for the help.
Derrick

 

323's are a 10 bolt ratio.
327's are a 9 bolt gear and your rite with either of those you have a series 3 carrier.