Hi Gelbster,
did a little online research. FEBI Bilstein which is a well known after market supplier for OEM parts (not a dealer) lists the hydraulic lifters for Porsche.
Measures
lenght: 24 mm
outer-diameter: 33 mm
Part numbers:
BMW 11 32 1 748 884
Porsche 996 105 041 50 <- make 100% shure these are the right ones for your car.
Febi Bilstein 07589
Link:
Herzlich Willkommen in unserem Internetkatalog
Info:
http://cars.febi-parts.com/download/Ventilspiel_D.PDF
Also searched the INA online parts catalogue:
medias® professional – Product catalogue
But no results for the given part number on the ebay website: 420004910.
INA in general doesn't produce hydraulic lifters. Their business is bearings.
Please check Porsche part number, because the 3.2 is not listed in the FEBI catalogue. Only 2.5 and 2.7 engines are listed! So make 100% shure that it is the right Porsche OEM part number for your car.
Because the FEBI part number is correct i would say go for it in general - if the Porsche part number is correct for the 3.2 engine. And make shure you get original FEBI Bilstein parts, which are high quality parts.
Regards from germany
Markus