[1991&135.0]

Ok this is me this is my current account I don't know why I was logged into the old one when I posted this tread anyway here is a picture inside, it's yellow so that would make it a 7 right? That with the 21 tooth would be correct for 3.73? I'm not sure if i have 3.73 but my speedometer has always been off about 10 mph like in the pic any ideas on how I can go about fixing that

 

[1991&135.0]

So if the speedo is correctly geared for 3.73s and the speedo indicates 70 when I'm actually running 60 would that mean I have taller or shorter than 3.73 gears or is something else the problem

 

[1991&135.0]

good to know see i have no idea what gears are actually in the rear end im thinking i need to open up the diff and actually count and judging by the rpm im thinking i have 3.73. does your car also have the yellow gear on the inside

 

[1991&135.0]

just put the car in the air and rotate the tire 1 full revolution and count the number of times your drive shaft turns. That will tell you your gear ratio in the rearend.

i have the engine trans and driveshaft out of it rn im guessing i can turn it and mark the yoke where the driveshaft connects