T-Case mod question

Ok - so I am slowing rebuilding an NP231J t-case (and by slow I mean researching and looking for beefier parts - it's my first rebuild). I found a 6-pinion planetary gear for sale on the cheap and in good condition and am told it's from a 1994 NP241C from a half ton Chevy 4x4. He doesn't know if it's the new or old cut gear. He says he rebuilt many 231's with this style planetary gear but I'm hesitant to pull the trigger. I'm thinking that this will not fit but I wanted to run it by the experts first.