K3 Alternators are
intended as a complete replacement unit for the original fitment alternators, for Porsche TM
911 and 914/6 from 1965 to 1989. More about them here.
Some early 3.0 litre Turbos had a 901 fan ring indicating a Type 27. However, the depth in
the seating for the alternator is intended for a Type 30. Please check carefully and match
the alternator to the type that suits your car the best.
Image 1 shows you the correct depth for ordering a type 27 and image 2 for a type 30.
K3 Alternators are
intended as a complete replacement unit for the original fitment alternators, for Porsche TM
911 and 914/6 from 1965 to 1989. 
