I've found the anti drain valves don't stop the oil from draining past the bottom end if left for a week or so. the standpipe keeps the filter filled to lower the time it takes to build pressure when starting.Yes, because the filter is orientated 'upside down' the oil drains back, the 'standpipe' up the centre is an alternative way of stopping that. Some filters have a flap disc behind the holes as a non return valve.
I've found a lot of them don't have the stand pipe when it does cross ref.Not a recommendation but I find this a handy website : Oil filter cross reference
Not sure if the alternative have a standpipe.
Can I ask what is the standpipe, is a check valve?
Yep, iirc it was a head off project. (I was 10 at the time!)The OHC engines used taper seat plugs IIRC, which were always hard to get out, but the heads used to crack between the water jacket and the plug hole, rusting the plugs in there, and that was normally the rearmost plug, so you had no chance of getting those out.
BT216 I think is the Baldwin number. You can buy from big machine parts dot comFram PH2821A, though I’m not keen on Fram. I’ve got a Baldwin number too, I’ll post that a little later once I dig one up.
The filter requires both the standpipe & the antidrain valve.
Yours
Vern