I changed out my thermostat from a 160 degree to 195 degree. Before the change the factory gauge gave readings about medium or a little past on the gauge. After the change the gauge needle pegs out on the high side. It is a small block with a replacement temperature sender.

I know for a fact the the early 2nd gen Camaros had problems with calibration of the replacement senders to the gauge. Anyone know if this is also true with the 1969's?

I fixed my 1971 gauge sender to gauge with a 15 ohm resister between the gauge and the sender.

Changing from a 160 to 195 deg stat should have shown a small increase in temp on the gauge as the higher rating stat is going to force the system to get to 195 before the stat opens. I guess if there was a problem in the upper range of gauge calibration what you are seeing could happen.

I am more inclined to think your stat isn't opening though and that is what is causing the excessive temps.

Do you have the same sender in it now that you had before, or did you change the sender when you changed the thermostat?

It is the same sender.