I know theres a simple formula to figure out the gear ratio and I cannot seem to figure it out. With one full rotation of the tire, I get approx. 1 3/4 turn of the driveshaft.

 

its a bit more precise if you rotate the tire 5 or 10 times and count the driveshaft. divide the two. exp. 5 spins of the driveshaft divided by 2 spins of the tire is a 2.5 ratio

you need to spin wheel more, from what you give you come up with a 1.75:1 ratio, which is far from, what it is.

keep on spinning

 

Alright so I finally got to doing this. So with 5 full rotations of the wheels I only got 8 and 3/4 rotation of the driveshaft... I am very un-happy with my current situation.

Somethings not right. But I counted correctly I am sure of it

 

Any thoughts? Another thing...

I know the gear is poor because at 75 mph i am only at 2,500 rpms

 

=(

 

I've done it 2 ways. For posi rears, just one rotation of the tires should give 2.5-3.5 rotations of the driveshaft; meaning the gear ratio is 2.55:1 up to 3.42:1. It's the same for a non-posi axle, but only let one tire rotate, and make it go 2 rotations.
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My guess is that you have a 3.42:1 because that 1.75 is far too close to being half your gear ratio.

 

at 60mph, are you at 2K rpm? that is where I am with my T5 and 3.42 gears.

 

its time you just pull the cover off and count teeth, its not working for you any other way, and im sure the gear oil is in need of changing anyway.

 

Yes

 

Save yourself the counting the gear ratio is stamped on the od of the dr gear.