Well I dunno how it will fit in an OBS, but I do know you can make a 2007 and ups rad fit in a square pretty easy.
https://www.amazon.com/Radiator-Chev.../dp/B07G4JXXZP
https://www.amazon.com/Seasons-76016...Silverado+1500
These are what I use Rob.
Where did you get your driveline from?
Bubba