So my header flange does not match my test pipe flange. I was told that even though the outer diameters were different the flanges would be the same. Do flange adapters exist? I have an Ebay header O.D 2 inch and a Blox test pipe O.D 2.5 inch. I did a lot of researching and i could not find out a clear answer.
Thanks.
P.S. (The only reason i got an Ebay header is because I don't plan on keeping the engine long term)

 

find a flange that does fit and have it and an exhaust reducer adapter welded to the end of the cheap-o header (after cutting the original flange off).

flanges can be found all across the web if your local parts stores don't carry them. Amazon.com has good prices as does Summitracing.com. look for 2.5" 3-bolt flange (assuming 3-bolt) and 2" to 2.5" reducer/adapter. I think the ones I got were Walker brand- good quality for the price.

 

Thank you for the suggestion hondamark35! so in your opinion, is the reducer necessary? because the test pipe is beveled. Also if the reducer is welded on, is the header outlet gasket still needed? (sorry for the noob questions).

 

If I understand correctly the situation is that you have a 2" header and a 2.5" test pipe. to get a 2.5" flange to fit nicely at the end of the header -where you've removed the original flange- a reducer (an "enlarger" in this case, if you want to think of it that way) will fill in the gap so to speak between the 2" tubing and the 2.5" opening in the new flange. a transition from 2" to 2.5" at the end of the header.

did I explain that well enough? it makes sense in my own head... haha.

you will want to use a gasket or appropriate sealant if you don't want leaks.

 

Haha definitely makes sense. I was just making sure. Thanks again