it does have a coil mount.

never seen a pipe plug in that spot on a intake. if its in the cross over? or it could be an oil dump for an oil cooler if open to valley? definitely has a cast in boss for it.

water by pass fittings looks to be plumbed for Indust/boat engine with water cooled exhaust manifolds maybe.

looks to be an early non emissions 318 intake. it does have bosses for v style a/c comp. 273 had a single plane 2v intake so don't think it is 273. could be from larger Industrial truck app.

I agree 67 or newer

I wager a boat engine or larger truck chassis.