I remember you said you have a serpentine set up on it? Just a thought, are you sure the pump is turning in the right direction? Can you post some pictures of your set up?
That's a good catch, magnum serpentines spin the water pump the opposite direction. Also, a lot of aftermarket serpentine systems have underdrive pulleys. More horsepower, but less flow. So, what kind of serpentine system is it and which way is the water pump turning?
But, 220 in traffic and fine on the highway? That's not insanely hot. I mean, it's too hot, but that could just be the lack of a fan shroud with that mechanical fan. You lose a lot of efficiency without a shroud.
