I have tried three different stats in my truck. The Hypertech 180 did very little for a temp decrease. The stock stat with bb mod and hypertech 160 both keep my truck between 180-184 year round according to atap.
The scaleing factor Flyer mentioned sounds about right by my comparisons between what my guage and atap reads.

 

My 34" rad was $74 from ebay! I love that place. My temps came down noticably with that and it drops right in...

 

So does anyone have the "Hypertech" thermostat, and if so does anyone know if they are just repackaged Motorad thermostats?

 

I bought a 160 degree Hypertech thermostat for my 01. It came in the Hypertech box but was marked Motorad Germany on the unit itself. Worked fine. Temp guage showed 175 degrees even at sub zero temps which leads me to believe that the temp guage stinks. Not sure what your truck has in it for stock temp but the 180 will not show you much of a change I would imagine. All the trucks I have bought here come with a 195.

 

i believe the problem is more the location of the sensor, not so much the temperature of the coolant right at the thermostat housing. this is pretty common.

 

take out the Tstat again and check it by dropping it in hot water with a thermometer and check at what temp it opens up