If I am not mistaken, the Supra flange is only a 4 bolt flange. As for the extra area on the flange on the previous link, I don't think it matters since the mating turbo flange doesn't have that extra material.

This looks like a custom downpipe to fit a Nissan RB20DET or RB25DET turbo. Most likely for a S14 (Nissan 240sx) with an engine swap. Dual oxygen sensor bung, one is for engine O2 monitoring and the other for a wideband.

References:

http://www.sonicperformance.com.au/95240/Turbine-Outlet-Flange-Suits-Nissan-R...

Reason:
I have not penalized this answer because I have another question for you. While it looks very close, the turbo outlet on all of the 240sx, skyline and RV20DET that I find have an extra area of coverage than mine (it would be the top-right corner at the bolt hole in the link you sent). Does this matter? Could you find any flanges that DONT have that design? I was going to accept but saw a SUPRA that looked the same, too.

If I am not mistaken, the Supra flange is only a 4 bolt flange. As for the extra area on the flange on the previous link, I don't think it matters since the mating turbo flange doesn't have that extra material.

References:

https://rbfactory.shop/products/nissan-skyline-rb20-rb25-t3-turbo-dump-flange