A little cut and paste from my conversion article. The coated ones were for the swap to a 38r and the other ones are from my OBS. The driver side manifold has a longer outlet piece.
SuperDuty Drivers side exhaust manifold F81Z-9431-AA which is a Ford Only Item
There is a difference in length at the outlet VS the OBS manifold. I am aware of others that did not swap out this manifold using standard up pipes but I was I wanted to be sure on the alignment with the bellowed up pipes.
I also purchased a new SD passenger side manifold at International to send to be coated. I think the OBS manifold would have worked fine. International 1831025C1 or Ford F81Z-9430-AA