wat size gears are in the rear end... and wat gear would i need to put in it when i get bigger tires....

 

Check the RPO sticker on the inside of your glovebox for one of the following codes. The different gearing options varied with different options that came on your truck. There wasn't just one set size that came on all Blazers/Jimmys

GU4= 3.08 Ratio
GU6= 3.42 Ratio
GT4= 3.73 Ratio
GT5= 4.10 Ratio

 

And as far as what you need for your new tires, that's dependent on how big you go. 4.10s would be great for a 33

 

oh ok ill give it a look