2000 A6,lets talk turbo wastegate housings
 

I am replacing 2 turbos on a 2000 a6 2.7 Quattro,numbers on original turbo are 078 145 704, k03/70 ID 710010886, this is passenger side. Replacement turbo is 5303 988 0017 , k03-017 LB 50150807. The problem is not with the turbo,its the wastegate housing, the original has provision for oxygen sensor,has large 4 bolt circular flange at catalyst , the replacement turbos have smaller egg shaped flange, I want to switch over the wastegate housing but 1 has a crack,so slight but????This problem exists for both left and right sides. Anyone ever see this?
thanks,
stu

If you are going to replace the turbo just go wit K04s. Its a simple swap and you'll be happy about it.