Ford Repair: overheating, degree thermostat, ford mustang

Question
I have a 1995 Ford Mustang it originally come with a 3.8L v-6.  Someone took the engine and trans out and put a 351w or a 302 in it.  I have already put a 16" electric fan and a 160 thermostat in it. My problem is that it will run under 200 degrees sitting still and it mainly heats up if your going down the road. It is a carburated engine,it has an edelbrock carb and intake. Could you please help me?

Answer
Ray-

  My guess is the problem lies in the radiator.  This problem would be worse if the radiator is the original V6 radiator.  The V6 radiator is too small to cool a V8 properly.  If it's a radiator for a V8, then I'd have it pressure tested to see if it's clogged.  Either way once it's working right I would replace that 160 degree thermostat with a 180 degree unit so the engine will run a bit better.  Hope this helps.

Steve