Havent done a dealer vin# search yet, but my "new" blazer (2001 LT) does not have an RPO code for a rear diff ratio that I can identify at least. None of the codes start with either "G" or "H" and the two that start with "F" don't come up as drivetrain info on any web page i can find (FK3,FK2). I searched around the passenger side rear for something and zip... I do know it has the Z85 configuration if that helps.

 

wanna take a pic of the rpo label? You can also see if you have limited slip by jacking the rear up (level ground,blocks on front) and spinning the tires. if both spends forward. Win.

 

I can't seem to post the pic, because my computer is out of memory and I don't need Samsung's Kies software that bad. Here's the label info...

107 0
aj1 an3 ap9 au0 au3 axp a31 b30 b04 cf5 c25
c3t c49 c60 dh6 dk2 dk7 d55 d96 eva e55 fk2
fk3 gu6 jc1 k18 k34 k60 l1n l35 m30 nc1 ng1
np5 np8 n33 n40 n90 qbf rsa ryj r6m slm t61
up0 up8 u16 u73 u89 vxs v54 v73 xbf x88 ybf
yc6 yd3 yd5 yd6 zbf zm8 zq3 zq6 zy1 z85 1sd
1sz 11u 12h 121 6wj 7wj 91a

bc/cc U 382e 12h

 

found it! you missed it bud. gu6.you have a 3:42 open rear end.

i win! lol

 

Hmm the code comes up now... I did try that one out of suspicion last night... anyway's It's just the daily driver for now, My trailblazer has the locker...but no trans =( Thanks for the quick response.