How can I tell if my recently purchased 98 TA WS6 has a stock rear end? It has M6 tranny if that is of any help. The car I bought accelerates very fast, so I'm thinking a previous owner may have installed some lower gears.

 

https://ls1tech.com/forums/gears-axles/376207-want-know-effect-changing-gear-ratios-look-here-first.html

Go to the attached file and look at different gears start with 3.42, 3.73, and 4.11. Then go out driving and put it in a gear and a certain rpm, record the speed then check the different charts for gear ratios.

 

4th gear at 60, and your rpmwil ltel lyou what gears you have

 

Used the calculator and apparently I have 3.73's. Verified my RPM at 60 and 70 in 4th. How can I tell if my rear end is stock or hopefully a 9 inch or 12 bolt w/o taking it apart?

 

just by looking at it should pretty much tell you, the stock 10 bolts axel tubes are pretty thin the 9'' and 12 bolts are pretty damn thick. Another good indicator would be to take the center caps off your wheels and see if there are different axels. The center section of a 9" and 12 bolt are quite abit bigger as well. hope that helped

 

look for 10 or 12 bolts on the rear cover, if its smooth you have a 9 in if there 12 bolts u have a 12 bolt and 10.