I usually only post on the Facebook groups, but trying to start posting on here as well. I was recommended these headers about 4 years ago by another member of N52 N51 Owner's USA on Facebook. I'm not affiliated with the headers manufacturer/seller.
They are made by HZ Racing Parts on Aliexpress. They are AA "Replicas". Having seen both side by side, the only physical difference I could see was the merge being dremeled smooth, and the AA logo being welded on (On the Genuine AA)
They are confirmed to be what Roundelwork resells.
I bought my first set about 4 years ago and they took about 2 weeks to arrive with the upgraded UPS shipping on AliExpress. They installed perfectly with no fitment issues and no modifications needed. I did use all OEM gaskets and would recommend everyone else to as well.
I ran the first set for a year and with a flame tune and nitrous (They got hot) with no damage or cracking to the headers. I sold that set to a friend when I sold the car they were on and he is still running them.
I bought another N52 and so bought another set of the HZ Racing headers. They took about 2.5 weeks to arrive this time. I opted to have them coated with cerakote locally ($160). This dropped underhood temps, and made the headers safe to touch not long after turning off the engine. I have been running these and still do for about 2 years now.
The listing changes on AliExpress and from different accounts, so the correct headers to look for are the ones with an HZ Racing Parts watermark in the photo, and the o2 sensor bungs at and after the merge, not on a single runner. It will say USA version, but I always recommend messaging the seller with the correct o2 bungs circled to assure the correct version is sent.
So far about 20 people I know on the Facebook groups are running these with no issues.
As for fitment on 128i and 5 series, I can't speak on it as I have an E90. But I know of two people running them on 128i.
Again I make $0 if anyone buys these, just sharing a good deal that was shared with me.
Link to headers-
https://www.aliexpress.us/item/32568...d=yL2FKfDMHp29
