5.9l oil pan

I would simply use silicone or "maybe" (been wanting to try) "right stuff" in the corners

Back in the seventies when I put a SB in my old Landcruiser, I did not use EITHER of the LA rubber seals. The ENTIRE LENGTH of the front/ rear pan cutout was sealed with silicone.......Didn't leak, either.....

On a side note that pan was "created" by cutting a small piece out of a 340 car pan and a 360 truck pan, and swapping them pan to pan and welding the pieces back in........to make the 340 pan "a 360" and vice versa. LOL