My Service manager just left and gave me a Mantis Racing (new style) underdrive pulley for free.
I have to give a big thumbs up to the guys at GSR. I am in Australia and asked them some questions about the right sized belt including shipping from the U.S. - They were really happy to help out and insisted that I buy it locally to save money on freight. They gave me the model number and what vehicles the shorter belt is used for to help cross-reference other brands - excellent customer service.
Here is the link to the belt sizes:
HELPFUL HINT: What size serpentine belt to run when using an under drive pulley? - GSR Autosport Community
2003 Porsche Boxster
Threaded Mode
