3.0i headers

[lo_jack]

The E46 people are all in a similar spot, unless they are hardcore racers. The cars are worth 7k at best, and a set of ebays are an improvement over most every OEM manifold barring a couple of exceptions. Those exceptions cost as much as new ebay cheapies on ebay as it is.

There are subtle differences in the ebay selection. None have 02 bungs in the OEM location for M54. But some have two bungs each. They are not remotely in the same position as OEM, so good luck on your CELs.

Some will need more extension than others. Most all have 1.75 primaries and oval collectors. As far as design goes, there are basically two types on ebay: one where the primaries merge way down by the transmission, and some where they merge nearly right off the head, closer to an M3 OEM tubular manifold design.

Those, by the way, would probably work (and maybe the Z3 manifolds as well), but there is some wonky air injection system on those that you have to block off. There are plates for that people sell, but it adds to the cost. Then there is the problem that they are a 3 bolt flange. If you wanted to bolt a cat to it there...great..but not useful if you wanted to put the cats later.

Some come with extra bits of pipe or clamps, but nearly all of the longtube kinds are just a pipe at the end, no flange. Some do include bolt together flanges, but not necessarily the 2 bolt kind that mates to the OEM midpipe.

Anyway, RB is right, you can get nearly all of them to "work," but there are some variables to look at that could make one better or worse for whatever you want to do, mostly hinging around cats. I think the only really important thing is to watch how many studs it takes to bolt them up and where they are located.