On the highway I see coolant temps at 190-192*F. Driving around town I see 220-226*F. The highest I have seen it read was 235*F. I don't watch it all the time so I wouldn't doubt that it may have gotten higher.
My '96 Cobra was the first model year production with the 32V engine. Many people complained of cooling problems to where Ford supposedly upgraded the radiator and reduced the fin count on the A/C condenser to aid in cooling. Warranty would cover the cooling issue for '96 owners and Ford changed the design starting with the 1997 model year. Mine never received the 'cooling fix' due to some really dumb conditions that had to occur first before they would do the work. Anyway, many times I would see > 230*F+ temps for the 9+ years I owned it. Never did I have a problem. From that experience, I learned to worry about other things.
is there any negative side affects to running at a lower temp then stock??
I can't say anything specifically for the V but running too low of a temp in a computer controlled engine can cause some self-tests to not perform which could lead to a check engine light. Other things may occur: emissions may go up (a concern if your state does the 'sniffer' test); engine may not go into closed loop quickly enough or at all leading to lowering gas mileage; engine may run rich lowering gas mileage and causing cylinder wash; thermal efficiency may be lowered too. I don't think operating a 180*F thermostat would cause any problems. A 160*F may be pushing it but since the radiators in these cars are the bare minimum, the engine may still see 190*F+ temps on a warm/hot day.