Mag vs Alu case

[Woz]

Hi,

I have a 1968 911T 2.0 (SWB - Euro version).

According to Page 49 of Wayne's excellent book 'How to rebuild and modify Porsche 911 Engines' this car should have a case that is made from Aluminium and an intermediate shaft that rotates directly on the bare metal. (My local Porsche mechanic also confirmed it is an Alu case). However, my engine has just gone through a total rebuild and inside were intershaft bearings (that needed replacing). According to Waynes book, these bearings should only be found in magnesium blocks. How can this be? What factors can cause intershaft bearings to be used in an Aluminium case?

In case it helps, my engine number is 2080585 and the VIN is correct for the year and model.

I also attach a picture of the open case.

Thanks.

[Steve@Rennsport]

Woz:

It sounds to me like someone machined your case for the later style insert bearings.

This is something that we've done (as well as many others) to these cases since 1970 for durability.

[Woz]

Thanks Steve.