DiabolicalDave

Showing my ignorance... I have a "built" 540 big block in my '66. For many years, I ran the WIX 51061R oil filter that was recommended by the engine builder. After I moved to Portugal, and those became very difficult to source, I swapped over to a FRAM HP4. Now, the engine is ready for another oil change and I happen to have four ACDELCO PF35L oil filters on the shelf which I bought for the other engine I'm having built. So, now I'm wondering if I can use one of those four PF35L filters on my 540. I started googling what's the difference and I realize I don't know much about oil filters.

Please educate me. Is there a pdf or website I can go read which will explain the significance of having a bypass and other things like that at a high level but in enough detail so I feel like I know enough NOT to be dangerous?

Thanks in advance.

SEVNT6

PF35 is the filter that came on BB motors. It's now called 1218.

Both Wix & AC are good filters. Fram, not so much...

DiabolicalDave

So the old ACDELCO PF35 is now called ACDELCO 1218?

SEVNT6

Yup, and it's little brother PF25 is now PF454.

The PF35 was a longer version of the PF25. It was known as the "truck" filter because that's what they mostly came on.
I've always used the 35/1218 on the Vette because of it's greater filter area...

TxLefty

Interesting information from 2023:

At present, ACDelco Oil Filters are commonly made and supplied by Champion Laboratories, aka FRAM. These filters are made in China but supplied to various parts of the world with the label “Made in America”.

2024:
Presently, Champions Laboratories Inc is a subsidiary of First Brands Group, a global car part manufacturer. FRAM, another renowned oil filter brand, is also a subsidiary of First Brands Group, and reports indicate that it also provides ACDelco with oil filters.

It may be that the ACDelco filters are built to higher standards than the FRAM filters. They seem to cost more.