Learn from my stupid mistake. My local AutoZone stopped carrying the Fram PH16/TG16 filters that I've used for forever, so I bought the STP S16XL that advertises itself as a direct replacement.
(For reference -- I drive a '73 B that uses spin-off oil filters.)
It's *close*... and on the outside, identical. But inside it has a metal platform that reduces clearance by about 1/2" to 3/4" -- enough to block the oil output tube on the oil filter adapter.
That blockage created an air bubble that killed oil pressure on my engine and touched off a month's worth of trouble-shooting and came within an ace of me removing my entire engine to pull it back apart -- until a friend of mine suggested the obvious solution, which I'd already dismissed.
Don't me like me, and don't make this mistake.