i am trying to find out the gear ratio of my 89 s10 blazer 4.3L V6 4x4, i looked in the glovebox for an info sticker with no luck. i am also almost positive it is all stock....for now he he. anybody got any ideas where i can find for sure what the ratios are??

 

You could pop the rear diff cover and read what is written on the ring gear. Or you could manually figure it out by rotating the tires through 1 revolution while you count the revolutions of the driveshaft.

 

the rear diff. has GM24 stamped on it does that relate to the ratio in any way?

 

that is a casting number. no help there.

 

gm is real bad about not spelling out what you have, the book for my '97 says i could have one of 3, but doesnt say which one i may have. on my ranger there is a axle code on the drivers door sticker that you can reference with the owners manual to know what you have. with the g.m. you 'bout have to mark the drive shaft and count the revolutions as you roll the vehicle forward 1 full tire revolution. almost 4 turns would be 3.73, a little over 3 would be 3.08 and close to 3 & 1/2 would be 3.40's im hoping i have 3.73's i tried doing mine with the rear tires off the ground but only i tire would turn and the spider/side gears in the diff mess up the equation. i'll have to manualyy roll the vehicle and try and figure it out that way. owners manuals are so worthless these days....

 

Thats what the RPO sticker in the glovebox is for racsan. If it is still there, one of the codes will tell you what you have. It is the "GU" codes. The GU6 code for example is 3.42

 

o.k. id seen that glovebox sticker, but it didnt make any sence to me. mine does say GU6, which makes sence as i dont think it would get the kind of highway milage it gets (22) with 3.73's and its too peppy to be laden with doggy 3.08's. thanks for the info!