Your truck is brand new already, on the inside, by replacing the parts bits by bits as you are doing. Yes, it is always best to tilt it sideways, even when pouring any liquid. It reduces the chances of spilling.
Good to know you it's back on. Ready for more work. I love the way you take care of everything you have. That's a good maintenance culture. They get the job done, so you gotta. Well done Papa.
NB: hahaha don't learn how to replace that yet...hahaha i might start calling you superhuman if you do.