I put I winter thermostat in and topped up the coolant
The temp gauge reads 80 when I've been driving for a little while. Is that normal ? I get very little heat in the cab
What should I do

What kind of thermostat did you put in?

I'd run a 180* year round.

Please define a "winter thermostat".

And is that in degrees F? Or C?

Don't forget degrees http://en.wikipedia.org/wiki/Kelvin!