I realize I’m late to the party, but I (finally!) have a used set of each on hand and it turns out they don’t want to mate, as can be seen below:
It was my understanding that the smaller, separate-runner manifolds (06 C253 031 H / 06C 253 032 H) were a bit longer than the OEM log manifolds (06C 253 031 J / 06C 253 032 J), but it turns out the bolt pattern for the manifolds’ output flanges is smaller / narrower than the one for the downpipes’ input flanges:
There appears to be sufficient room to slot the bolt holes in the downpipes’ flanges by a few mm so the manifolds will bolt on, so this isn’t a big deal (and I’m adding cats to the downpipes, so I can easily compensate for the difference in length of the manifolds as well), but I haven’t found any mention of this being an issue for anyone else, so I’m curious: Has anybody else done this? And if so, did they have to deal with the same issue? Alternatively, has anybody tried using 3.2L exhaust manifolds and/or with JHM’s downpipes?
P.S.: I see that JHM is no longer listing any headers/downpipes/exhaust systems on their website, except for the 3.0 downpipes … what’s up with that?