901 Transmission Conversion to Posi Rear

Is it possible to convert a 901 tranny form non-posi rear to posi rear? If anyone has attemted or completed this type of conversion, please comment on the process.

What did it involve as far as parts and labor? What was the total investment in effort and dollars? Was the result as expected?

Keep judgements to yourselves(BK,AN,etc.) and please comment if you've had experience with this type of project.

As always the positive input is appreciated. Thank you.

Rich

I have a 901 trans in my 914/6 3.0.

I purchased a Quaife Limitted Slip Differnetial (LSD) from GPR....800-321-5432, ext 502...Dave (owner).

The LSD will take the place of your original differential. I paid $1,200.00 for the unit, and had a trans shop do the install on the removed 901.

Except for blowing first gear due to excessive hard launches at the autocross, it has been a great upgrade. I would advise using a good trans or doing a rebuild while you're at it....

I road race a 1971 911S in the PCA club race series and just did the conversion you speak of. I took a later ZF factory limited slip that had been set up in a 915 and had Tom Pertruschka of Mayo Performance in Euless TX do the fit up in a 901. The unit bolts right in. The only problem is the output flanges. Your stock flanges will not work because the splines are different. I used flanges out of a post '74 915 (I think). This requires you to use SC axles and inner stub axle. It might be more cost effective to use the Quaife as from what I have seen in the ads, it might be cheaper than a factory ZF. I use the ZF to keep me legal in stock class. If you are racing of autocrossing, you might want to check the rules first.

JB