I thought all late model EFI 302's have a fitting in the sump. I know our old 1992 model did.
Just buy a threaded fitting that
oil temp sender will screw into, drilled out fitting in sump to correct size and silver solder or tap it for threaded fitting. Been so long ago I can't remember if you tap it or solder it in. I've seen Warrick Harrison do a few of these, maybe ask him at next club meeting or give him a call.
Also don't you need to get compatible senders to work with those guages. I know with VDO you need to get matching senders.