How to buy the right fitting radiator?

The extra capacity cooling system is option code V03. You do not have that. You have the transmission cooler because it's an automatic transmission. They all were. As for the engine oil cooler. Looking at the driver's side of the radiator, do you see two metal lines screwed into the radiator? If so, you have the engine oil cooler. If not, you do not have the engine oil cooler. Now, if this vehicle is running hot or overheating have the coolant tested for exhaust gasses before you put any money in it!! Your deVille has a Northstar engine in it. All Northstar engines blow head gaskets sooner or later and the only way to do the job is to remove the engine and transmission from the bottom of the vehicle. There's no other way!! It's about a $3500+ repair that, at this point, would not be worth it. Hope that helps! Jim