this is what i did my trans-am originaly came with a 9 bolt 2.77 posi i replaced it with a stronger rear end its now in my car its a 9 bolt 3.27 posi but my problem is that my speedo on my dash does not read acurrately it says im going like 70 mph but im doing like 60 mph the car is also an automatic that was rebuilt if anyone nows whats wrong and nows how to fix it please let me know it would help me a lot i cant stand knowing that my speedo is not reading right

 

You'll need to change the drive/driven gears in your trans with ones that are appropriate for your new gearing. Check the stickies out at the top of the page.

JamesC

 

i read a sticky that had the best possible combination for a 245/50r16 tire witch i have and my rear end is 3.27 ratio it said i need a 44 tooth driven with 17 tooth drive now that i got the combination of of gears is it expesive to buy these gears and is it better for you to do it your self or should u send it to a transmission place and would it be expensive

 

You should be able to pick up what you need from the following company:

http://www.transmissioncenter.net/sp...n_______va.htm

With a little research on TGO and/or a manual, you should be able to swap the gears yourself.

JamesC