Is there a reasonably possible solution using the stock E46 M3 headers?

[butters]

I'm still at the early stage, I don't have a motor, but as I shop around I'm thinking about what I would want to get from the donor car to make life easier, especially if I buy a motor from a dismantler.

I like the idea of using the factory BMW-designed headers, but of course they won't fit in the E30 due to the massive catalytic converters. Has anyone considered or seen/done modifications to make them fit, i.e. cutting out the cat sections and putting a flange at that point? Would the bends of the primaries allow for it?

I have a custom exhaust so I see fabrication in my future regardless, and I'm thinking I may as well see if I can get the headers with the engine, cut out and sell the cats for scrap, and then connect my exhaust to the headers from there. I'm not too keen on eBay "stainless" headers.

[diesekte]

Has anyone considered or seen/done modifications to make them fit, i.e. cutting out the cat sections and putting a flange at that point?

S54swap.com/kassel did this

Unless you're doing it yourself, why bother? The ebay headers are hit or miss on flanges being lines up perfect, but they're about 150$. The topspeed headers actually fit quite nice in my experience and aren't much more. They are like all aftermarket bmw headers...knockoffs of knockoffs that are way overpriced. The biggest gains are in eliminating the cats. If you want to stay oem just get the euro headers...sets all over fanatics

[superleggeram3]

I use stock S54 headers on mine but dont run cats (as I dont have to being a pre 88 car in the UK) - also the hulkhead was modified to allow that whilst allowing to moving the engine back over 2"s

[Staszek]

The Ebay ones are the cheapest but dont fit well and need work. CPI are great options but about $900, there are a few other headers that are also great fits but $1000+. If the Top Speed ones at $399 fit that is the route I am going.

[diesekte]

I bought mine through clown shoe motorsports in dallas, I would talk to them.I think they were very slightly cheaper than that, and they test fit them before selling them to me so I knew they fit. They literally are right down the road from the topspeed warehouse so they can make sure to get you ones that fit

[butters]

Seems like it should be possible, without moving the engine back. S54swap.com advises on this route as a matter of fact... But it's Kassel so idk.

I saw that FredK actually cut up his headers like I have in mind, but then eventually used eBay units: