http://www.pontiacbonnevilleclub.com/fo ... hilit=hail mary
so this is the GM Racing Torsen. Its a Zexel unit, making it the hands down the best limited slip/LSD that is available for the 4T65.
I will let the pics speak for themselves
This was a torsen that was used by GM Racing

Stock HD Diff on the left, the GMR Torsen on the right

the 2 parking gears. The Left is the stock park gear with bearing, on the right is the Torsen Park gear with a larger bearing. It also appears that the Torsen park gear is machined to accept that bearing.

The teeth are different although the part number is the same

Sun gear side

the sun gear with the modifications for street use. It also appears that the sun gear is heat treated compared to the stock unit

also a pic of the copper washers on the planets to make the unit for street use.

I will get to test it out here in a few weeks with my Hoosier Slicks













