OBX header collecter size?

[Devens240]

is the collector on an OBX header 2.5" or 3"? ( the part that bolts up to your cat back)

[S14DB]

2.5" ID, 4" flange.

Watch out for some of the no-names on ebay. They have a 2.5" ID but the Bolt holes are less than 3" apart. So if you use a 3" Test pipe on some of them you'll get a leak. Using a 2.5" gasket fixes the problem. Have not seen this problem on the OBX brand. Only on the no-name ones.

[Devens240]

ok thankyou sounds good