Intermediate shaft.

[Cupcar]

What is difference between the usual intermediate shaft used on a 2.7 to 3.2 engine and the 964/993 intermediate shafts?

I understand that the early 964 shaft has a steel gear and the later 993 shaft has an alloy gear (or vice versa?).

Do all the shafts use the same bearing bore in the crankcase, the early shafts have bearing part numbers starting with 916 and 901, later shafts use bearings with a part number starting with 996s

If you had you pick of intermediate shaft which would you choose?

Thanks