So I replaced the water pump, installed a 180 deg thermostat down from a 192 deg, get it all buttoned back up filled her with properly mixed anti-freeze and added purple ice. Before if I kept below 70mph she would run at 192.2 now she runs 195.8 and gradually climbs... WTF! I could keep her temp down if I needed to by running the heater, not now...

 

Geez. Rover tricks.

Almost surely some air somewhere in the cooling system.

 

Air in the system definitely

 

There are kits that will create a vacuum on the cooling system allowing you to draw coolant from a container into the cooling system without the possibility of air coming into the engine.

 

Besides air are you sure you routed the serp belt correct?

 

What is the difficulty level in installing a 180 degree thermostat?

 

Could also be a faulty stat. When I swapped mine the Stant Super Stat I purchased was faulty out of the box, tossed in a NAPA stat and no problems so test before installing.

 

Depends on whether or not you shear one of the bolts off like I did.....

 

I'd go with air bubble. I put a new radiator in my son's D1 and it ran fine then it started heating up again. I jacked up the right front and fired it up and the coolant level dropped looking through the top filling port. I put another 1/2 gallon of coolant in it. Been fine ever since.

 

Might this be helpful in removing air from the system
Stealth Conversions V8 Cooling System Parts - Coolant Sight Glass