[Cobra72]

Had the ECU/engine re-mapped on the dyno last week and found electronic water pump controller faulty so replaced with new Davies Craig lcd unit. Engine is running sweet, but temperature gauge rises above 100 degrees after about 20mins driving, water pump and thermo fan appear to kick in around 90' but engine still consistently above 100' (and as high as 120') in traffic. I also note the gauge can fluctuate rapidly between 95' & 120' (ie, 30secs to 1 minute)

1. Could this be a faulty thermostat?
2. If so, what thermostat should I replace it with (160' or 180') (302 Windsor)

Appreciate your thoughts.