If you follow the write up.. you should be fine.

Lube the rings so they don't get hurt going in. Wiggle elbows as you tighten so they don't end up with pressure pushing them into a 45 degree and ... that's about all there is to it. If you want to go aluminum.. do it. I wouldn't put any additional value to them vs the plastic though. Especially if you have to pull things apart later and you pull the wrong way and break a timing cover. That's...what the difference in plastic vs aluminum would be.