Need advice on installing an oil filter adapter

Mike - you may find an o-ring on the nip for the plate adapter when you take it off. I didn't rember that, I don't recall if its used with a right angle adapter.
Here's a pic of some long tube check valve equiped ones. The one on the right is for a slant. One of the others, I think the middle, is for marine v-8.

chkvlvs.jpg