2008 GR Borla exhaust question... Need answers fast

Hey guys,

I just got a P&L stage 1.5 package, with a 3" catted DP. I have a Borla CBE coming in the mail, and I just read that it tapers down to 2.5" at the intersection with the DP. Is this true? Will I have to buy an adapter gasket to make this TBE setup work?

I leave in less than 2 weeks for school so I need to know fast, so I can get the parts I need and have it installed in time.

Thanks in advance!