ok first off...

the car you have is what? NA auto? if so then those arent your numbers....

if its an NA it has a 4.3 rear end.... you can check to see if its an LSD two ways...simply get under the car and look for the big red sticker that says LSD on the pumpkin OR lift up the rear end and spin the wheels....

most sport packages also had ABS, TEMS, a targa, and a spoiler....so those would be other tips as to whether or not you have a sport package.