What kind of running gear do I have??

Ok, so I have a '98 silverado k1500 with the Z71 off-road package, 4.3, and 5-spd. I'm just wondering if there is a vin decoder on this site or anything that can help me identify my rear-end, gear ratios, trans, transfer case, etc.

It should be on the build sticker usually located in your glovebox.  There is another thread here that has what the 3 letter codes stand for.

Hi!  Can anyone direct me to the thread that has the definitions for the 3 letter codes in the glove compartment??  I found it once, but didn't save it ...
 
Thanks for any help!!

This is not the link that you asked for,  but it has the info that you are looking for. 
 
Model Year:
http://www.angelfire.com/ca/TORONTO/VIN/VIS.html#year
 
Chevrolet Specific Codes:
http://www.angelfire.com/ca/TORONTO/VIN/chevrolet.html
 
You can find the codes on a sticker usually located in your glove box.  Also,  on your differentials,  there will be a tag help on by  a cover bolt.  It will have have stamped on it something like "8.8 3 42"  which is an 8.8" diameter ring gear at 3.42 ratio. 
 
I hope this helps.

http://www.****/forums/general-discussion/technical/107639-rear-end-ratio-rpo-codes-here.html
 
check out this site:  has differential codes and other stuff