With my current setup, EGT is 650-800 at idle, depending on ambient atmospheric conditions. At WOT and full boost around 1250 to 1300F. Cruising at about 60mph at narrow throttle angle, it is around 1000 to 1200F. When decelerating it usually drops to 800, then slowly rises to 1000, then at a stoplight, she will drop and stay at 800, at low idle after a run, it slowly drops to 650 range.

Your best bet is to install the thermocouple before you run boost, so you know what EGT your car was engineered to run, to establish a baseline. See my previous post for other info.