I just gave away my last core. The side tanks were in good shape. BTW I also using the share button sent Forest39 AKA Kevin .
Hopefully he will chime back in with the manufacturer information on the core he said he had found a new supplier. Out on the West coast radiator guys have been closing up shop. For goodness sakes if anybody has a good core at least save the side tanks if you have to make space in the shed...
PS I believe some of those radiators made to exclude the expansion tank also were made to handle more pressure, especially if the intake and the fill is on the passenger side. I'm not quite sure on the mechanics of that it's just what an owner told me.