What size gasket connects the stock header to the stock downpipe and could I use the same gasket to connect a 3 inch outlet header to a 3 inch downpipe.

 

You are speaking about the 3 bolt gasket right. You will need a new one. I would think the old gasket will be too small. Not sure where to get one.

 

are u sure or are u just making an educated guess?

 

Well the stock header and downpipe are not even close to 3 " are you buying an aftermarter 3" setup or what? Most things you buy will come with a new gasket.

I'm 90% sure. If the stock gasket isn't big enough you are screwed and I doubt you could modify it to work.

 

Was looking at this and they only sell the oem style one so im assuming that's the right one?

http://www.zzperformance.com/cobalt_...=630&catid=155