I replaced my carrier to 31 spline. Just slamming it all back together.
Marked the bearing caps with (duh) a paint marker. One dot for driver's side, 2 dots for passenger side.

Sat the left one down on the left side, right one down on the right side.

Cleaned up the gasket surface, hit everything with (again duh) brake clean.

My paint marks are gone. So I know left and right but I'm unsure if I have them upside down or correctly.
There are a couple arrows in the casting. Do they face in to the middle or outwards?

 

Look for the shadow of the cap on the case. you should be able to see a line where the edge of the cap was. You can also put them on and snug them up empty to feel the parting line one the ID.