Hi Gelbster,
thanks for the 99610504172 hint.
Did a little more research. The 420 0049 10 is the INA part number, whereas the 265010 the Ruville part number is. Ruville is a after market sub brand of the Schäffler Group / INA.
Ruville: Your System Specialist für Engine & Chassis.
Porsche somtines changes part numbers without changing, or improving the part itself. This is caused by the ERP system.
So in short 420 0049 10 is the INA OEM part for all 986 engines.
About price difference. It is quite normal that Porsche charges enormous spreads. In general it's hard to get OEM parts, because Porsche has contracts with suppliers. For example you'll never get after market SHW brake rotors.
Regards
Markus