220 is plenty warm and I would like to see more like 190-200 max,try a cooler thermostat,whats the coolant look like,if its rusty looking time to flush and change it,Ive also seen radiators plugged with bugs and crud so bad air couldn't get through. Just some things to try if you haven't already.
check your bottom radator hose. common problem on bb mopars. they can collapse and restrict flow down to 1/3. to fix this, just make a spring shape support out of coat hanger and put it inside the hose. this will add support so the hose wont kink.
hope i helped,
ps make sure the spring fits tight in the hose.