After getting all of the Corvette distractions behind me (at least for now), I can get back on the Nova. While the runaway temp issue had improved, it still was not right. After consulting with a few different people as well as some internet sleuthing, I decided on installing steam vent lines / 4 corner cooling through the intake manifold. As mentioned before, the siamese bore blocks can be a little tricky to cool, to say nothing for getting the air bled out properly.
So, I tore into it. Pulling the intake, drilling the rear on the intake for pipe threads, installing the fittings, and then piping the hoses to the front of the intake. I also installed a spacer between the intake and thermostat housing to relocate the temp sender. Additionally, I drilled a small relief / bleed hole in the 160 degree T stat to help with bleeding the air.
The cooling system bled out easily, and maintains 180 degrees in the shop with no real air flow.
Of course, no good project is considered complete without a road test.....
I am happy to report the car maintains 160-170 degrees on the road, will creep up to 180 at a stop sign. In all, a success!