Just for the heck of it, try to ID your engine.
Look-for and post-here the following codes: 1. Engine Serial Number
2. Block casting cde
3. Block date casing code
4. Head casting code
5. Head date casting code
It is supposedly possible to use either a full-flow or a by-pass flow oil filter (or, no oil filter) on a 1958-1963 261 engine/block.
