Yes, but there are good and bad copies... ,any results on dyno with those, anyone..?

Does anyone has experience with these headers maybe? They look like a btb copy.... they sold 37 of them so maybe they are not such a bad copy..? http://www.ebay.co.uk/itm/STAINLESS-STEEL-EXHAUST-MANIFOLD-FOR-BMW-3-SERIES-E30-6-CYL-320i-323i-325i-82-94-/220930769976?fits=Plat_Gen%3AE30&hash=item33708...

1st step: 30Nm
2nd step: 90°
3rd step: 90°

Order of tightening (bolts):


12 10 4 2 6 8 14>front
13 7 5 1 3 9 11
These numbers are for BMW OEM headgasket.
Its good to wait 15 min between 2nd and 3rd step.