I got a 97 ITR swap in my EK hatch. I tried searching the Type R FAQ here under headers and didn't find my question answered.

I notice that the flange on the stock header is pretty big and due to poor research, I went ahead and bought a blox 2.25" blox test pipe not knowing that USDM and JDM ITR headers are different by .25". The pipe flange to the header was barely big enough to cover the gasket donut.

I'm wondering if the 2.5" blox test pipe flange holes for the bolts will align with the holes on the header.

 

Also would I need spring bolts? And which ones if I do need them?

 

don't do it

you'll have a raspy shitbox for that extra 2hp

seriously, it really shitifies the sound of the exhaust

 

I really don't mind getting a high flow cat either. I just need something soon to order to replace the barely fitting cat I have on now (from a 98 ex civic). I read that ITR headers require spring bolts to the cat.

 

all of them do oem. gsr is the same way. the header to cat is a ball flange. you're in a fix though. aftermarket cats suck and will melt in roughly a year. the cats to have are jdm itr. they last and bolt right up