Oil Filter Adapters
 

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.

Re: Oil Filter Adapters
 

hello, ed. maybe i can be of help. the valve you are seeing is a bypass valve. your original housing also has one under the large hex shaped nut on the outside of the housing. as far as the gasket to use, take the housing you want to use and match the gasket to it. that is the reason full gasket sets come with 3-4 different housing gaskets. it looks like you have found the "Pontiac" version of the housing, using a AC/Delco PF24. i hope that this info has been of some help. as far as the position of the valve, take some compressed air and blow through the valve and see which direction that the valve opens. as this is a "bypass valve" it will open up when the filter is restricting due to being clogged.

Re: Oil Filter Adapters
 

I purchased a spin on unit that had that valve missing. I read here on this forum to use this one.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I've updated two engines with the valve in that position.



I had posted a photo of a gasket used, but was not sure if correct, so defer to Lewis Matkin's advice

Re: Oil Filter Adapters
 

Gasket numbered 70363 was the correct one

Re: Oil Filter Adapters
 

Thanks for the info and the photos, Funky!

Re: Oil Filter Adapters
 

Thanks for the explanation, Lewis. You've confirmed my suspicions!

Re: Oil Filter Adapters
 

There are actually 2 different spin-on oil filter adapters for the V-6. The one 'Funky61' is the 'Pontiac' style as Lewis Matkin pointed out. It uses a PF24 oil filter, same as a Pontiac V-8. I believe the GM part # for this adapter is 662066. The other type of spin-on oil filter adapter uses a Chevy type PF35 oil filter. That type of adapter is very rare and appears to have been used on '73 and '74 379 and 432 V-6's. I don't have a part number for that one.

Re: Oil Filter Adapters
 

https://6066gmcclub.com/album.php?albumid=63

I'm not sure who posted this album, but it shows the other type that Bob Bray mentioned.

Re: Oil Filter Adapters
 

Those photos are great, Funky! I'd sure be curious to know where Jeannie got them 11 years ago.

Re: Oil Filter Adapters
 

This is what I did to get a spin on oil filter.
https://6066gmcclub.com/showthread.php?t=51141

The machine shop charged me $850 to make both pieces.

Re: Oil Filter Adapters
 

$850?? I hope you meant to say $85?

Re: Oil Filter Adapters
 

I mean $850 (3 years ago) for a one off part (base plate and bolt). Now they want $1354.20 (rip off). This is an online service. They provide free design software and I used it to make a stl file and 3D printed it before submitting it to be made. Otherwise I would have to find someone locally to make it. 3 years ago I was still working for a living, now I'm retired and can look around for a machine shop for the next oil filter adapter.

Re: Oil Filter Adapters
 

There is a Genuine GMC spin on filter housing on ebay right now. https://www.ebay.com/itm/296163793681

Re: Oil Filter Adapters
 

Man. I'm glad to be able to access and know my way around a lathe and milling machine. I can manufacture such parts for a lot cheaper...