I didn’t take pics but yes oil (little discolored) from break in literally drained out during the initial draining. Crazy right! I just rigged hoses for quick block draining.

They are new dart big m blks. Just a thought if oil made its way into the hoses and not being circulated so to speak just stayed dormant in the hoses?? Might not of been as much as I thought but regardless.

Sure hope it’s not the blocks but both new coolers don’t seem possible either.

Some oil that dropped into water jackets from assembly and yes just got caught in the hoses? That would be my guess as they were "freshly built".