[Ed Snyder]

I've been on our forum since Jolly started it in January 2000. But I don't remember this topic being discussed before. So I'm looking for some advice.

I'm replacing the original oil filter adapter on the 351C in my '65 Suburban. The first photo shows the side of the engine where the filter adapter mounts.
The next two photos show the "old fashioned" original style adapter for the canister style oil filter with the replaceable element in it. As most of you know, these filters are messy to replace at oil change time. So I'm installing the spin-on style adapter which was introduced in 1966. These make changing the filter a breeze in comparison. The fourth and fifth photos show this adapter.

In the fifth photo you'll see a little spring-loaded check valve. I assume this is to help prevent oil drain-back when the engine is off. Unfortunately, one of the adapters I have has this valve installed the other way, protruding into the cavity at the top of the filter. So, I have two questions: 1. Which is the correct way to install it, and 2. Is this check valve even necessary? The original filter adapter I removed doesn't have a check valve at all. I don't want to install it backwards and prevent oil from flowing through the filter.

Just for information purposes, the last three photos show different filter adapter gaskets from some of the gasket sets I've bought over the years.