Just installed my exhaust system but I need the correct bolt size and thread to fit accurately. The two spring bolts from my DP to O2 couldn't compress all the way because the new flange holes are smaller then the OEM. Springs couldn't compress at all but the screw is in; Good or Bad? I also need bot sizes for the mid hangers and Flange. Oem was 17mm; new flange seems bigger. I tried contacting Buschur Racing but their number is disconnected.