This adaptor plate worked great in the long run, I had to shave the O ring because with no amount of force that could push the HKS blow off valve down to get the clamping ring into place. I measured the tolerance compared to another flange I had on a different car and there is about a 1mm difference in where the rubber O ring sits. Once the blow off was installed into the adaptor I had to get a reducer for my stock vacuums line to fit the HKS blow off. Also once installed on the car the blow off sits just high enough to hit the stock Hood ducting for the intercooler so I makes it and drilled out a 3" hole for the valve to sit with out rubbing all in all the install took me 35 min instead of 5. All in all the park works in the end and the gains from holding boost are worth it.