It's been so long since I drove an "old" v8, but I think 220F is right on the line for something pre-1993. It's not uncommon for 1st and 2nd gen owners to buy a radiator with an extra core or two to help combat higher engine temperatures, even with a "perfect" engine/cooling system. First thing you need to do is determine if your temp gauge is correct, this could be a simple as an incorrect reading because a sensor/sender is failing. If your fan clutch is sticking, that would create an extra load on the engine while cruising, which could also increase temperatures. Collapsed upper/lower hose, low coolant level in radiator, failing thermostat, failing head gasket, weak/inadequate water-pump for the location/temperatures? Can't think of much else.
220F could be completely normal for the current environment. Here in Florida, during Summer, I think my '80 Z28 ran around 200-210F with a 160F thermostat and the A/C running, and around 190-200F with A/C off. That was 3 decades ago though. I could be remembering wrong. 17 year old me was more concerned with the blonde in the passenger seat than engine temps.
