okay, I'm NOT looking to anything JDM and do not want a JDM header from anywhere. I am well aware that the JDM has a larger collector and will yield more gains.

I've also searched H-T already and I know that certain year Integras can BOLT-ON other years and models' header with ZERO modification, complete bolt on, no welding, no lengthening and no shortening.

If this is true why does DC Sports show different part numbers for some of these years and models if they are in fact interchangable? Are there differences to the design/diameter of the headers made by DC for there headers for different models?

In short, I'm looking for a DC Header 4-1 to replace a 97 USDM ITR header and I'm trying to find out if other GSR or LS DC Headers are an option for me to be COMPLETE BOLT-ON. thanks

 

Most GSR's have a different length manifold from the factory. The LS header will work.

 

how does the B16 header compare to the USDM ITR in length? are they interchangable?

 

any input from the day members?

 

Like Kendall said, you can use a 94-01 LS header to replace the OEM ITR one. It will bolt up fine to your cat, one o2 will be in the header, and 1 will be in the cat.

As for your b16 question, I am not sure about the length, but I think the height of the b16 is a little shorter than the b18, so you would have a problem getting a b16 header to fit on a b18. On the other hand, a b18 header would fit onto a b16 head with room to spare underneath because it is compensating for the taller b18.