Whose High Flow Cat?

With my planned exhaust upgrades I'm set on a 3" high flow cat. Vendors sell them for about 150 dollars; E-Bay has Magnaflow cats for 50 dollars. The E-Bay kind aren't flanged for our exhaust, I don't think. Wouldn't I need to weld flanges on either side of the Magnaflow to make it fit? Am I using the same dimensions as on my stock exhaust, excluding diameter (duh :))?

Here are pic's of what I'm talking about:

RRE cat: http://www.roadraceengineering.com/parts/dp/rredp-2gfwd-options.jpg

E-Bay: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33629&item=7964939218&rd=1

RRE: 150
E-Bay: 84* + cost of weld + pain in the ass.

Worth it? Is there a better solution?



*50 dollar cat, 10 dollar shipping, 2 12 dollar flanges

Edit>> On a side-note, do the high flow cats have 02 bungs already welded in, or is that something else to weld?

you could just put a test pipe on untell you have to do emissions.

You didnt mention what you currently have for catback and downpipe ;)

This is why I always sugegst buying a turbo back from one vendor. For example, the 2.5" downpipe, highflow cat, and catback that I got from buschur back in the day. Bolted right in, and nothing to ass around with. If you do the RRE DP and the catback they offer (N1) their cat will drop right in. Etc. Takes all the guess work out. If it was my car, I'd buy a 99 dollar unit from summit and weld on my own flanges, since I made my own exhaust.

So your options are basically do it all from the same vendor, or find someone you trust to make the csustom one at a time thing work.

you could just put a test pipe on untell you have to do emissions.

I've considered doing this, but my conscience tells me not to f-up the environment. I'm an Environmental Law major and when I drive my car to classes I catch shit for it being a "sports" car as it is.

You didnt mention what you currently have for catback and downpipe

Right now I have stock exhaust, but I'd like to put everything on at once. I plan on running an evoIII, no bigger. I have a ported evo 02 housing and a 3" n1 catback. I'll be buying rre's evo flanged short downpipe for drop-in use with either a test pipe or cat. I'm going to take your advice and wait until the downpipe arives, and see how big the gap is between it and the catback, then custom fab the cat and save a couple dollars. So far I've bought everything used, but prices are adding up. Thanks :)