R34 CUSTOM

Old topic I know but just a bit of extra information if this discussion is still valid for anyone. Z145A and Z442 are completely interchangeable. Thread is the same and regardless of the size difference the oil seal is the exact same size and in the exact same position. I'm not sure why Nissan changed it on the R34 but I can confirm that a smaller oil filter on an engine increases oil pressure while larger oil filters lower it.