Spin-on oil filter adaptors

[Patrick B.]

I hate the mess that the canister type filters for pre-68 cars make, and I am looking through my boxes of junk for suitable adaptors. There seem to be two kinds. One type simulates the top of the canister and retains the original aluminum by-pass assembly while the other type eliminates the by-pass. I understand that at least some modern oil filters have an internal by-pass so maybe the original by-pass is not necessary. Also I found two types of the original aluminum by-pass assemblies. One is marked 5573842 and I think this is a 67 original piece. The other looks different but seem functionally equivalent and is marked 3915164. A part number starting with 39 seemed to be too recent for the canister filter age.


Any advice and opinion about spin-on filter adaptors?

[Keith B.]

Re: Spin-on oil filter adaptors

i had two different ones on two different motors and both leaked. put the canisters back on and no leaks

[Joe L.]

Re: Spin-on oil filter adaptors

I hate the mess that the canister type filters for pre-68 cars make, and I am looking through my boxes of junk for suitable adaptors. There seem to be two kinds. One type simulates the top of the canister and retains the original aluminum by-pass assembly while the other type eliminates the by-pass. I understand that at least some modern oil filters have an internal by-pass so maybe the original by-pass is not necessary. Also I found two types of the original aluminum by-pass assemblies. One is marked 5573842 and I think this is a 67 original piece. The other looks different but seem functionally equivalent and is marked 3915164. A part number starting with 39 seemed to be too recent for the canister filter age.


Any advice and opinion about spin-on filter adaptors?

Patrick------

As far as the 3915164 goes, it's like this: beginning in 1968 virtually all PRODUCTION Chevrolet engine blocks went to the style cast and machined for spin-on filters. However, not all applications actually went to spin-on filters for 1968; some stayed with the canister-style filter. These included many trucks as well as police cars and this continued for several years after 1968. So, there needed to be an adapter for use with a block designed for a spin-on filter but actually using a canister-style filter. That adapter was GM #3915163 which may be marked 3915164 (the part number for the casting component of the adapter). That's what you have.

As far as the adapters to convert a canister-style block to a spin-on filter, there were/are basically two types available. One type uses a PF-25/PF-35 filter. Since these filters have no integral bypass valve, the adapter must include a by-pass valve. The other type of adapter uses a Ford PH8 filter. This filter has an integral bypass valve so no bypass valve in the adapter is necessary. The Ford PH8 filter adapter uses 3/4-16 thread size and the PF-25/PF-35 filter uses 13/16-16 thread size so you can't get them mixed up. Take your pick as to which one to use but most folks would probably be more "comfortable" with the adapter using the PF-25/PF-35 filters.

[Patrick B.]

Re: Spin-on oil filter adaptors

Joe --- Thanks for the good information. The PF-35 and the original 67 by-pass is the combo I'm going with.

[Roger W.]

Re: Spin-on oil filter adaptors

Very good information. I have an old fram adaptor. I will have to see what kind of filter it uses.