Radiator core sizing

I use the Rock Auto web site for this type of problem. They list parts from multiple suppliers, and those suppliers do a real good job of including pertinent cross reference information. I found two listings for around $115.00 to $116.00. They're listed as a 20 3/4" core, the second choice you listed.

The people at your local auto parts stores or radiator repair shops should be able to give you the same information, but it's a pretty good bet you won't get as good a price. I ordered a radiator from Rock Auto for my '88 Grand Caravan a few years ago. It was from an aftermarket supplier and fit and worked perfectly.