I took the NC30 apart to see how its working thermostat situation looked like. It turns out the NC30 housing also lets the thermostat rattle around.
Both thermostats are 82C rated.
So when I first took mine apart and tested it, I remembered it flowing a lot more water than the bypass hole should allow. I redid the flow test comparing both the NC21 and NC30 thermostat housing, with the new and old thermostat for the NC21. They all flowed a small stream. It is possible at some point there was a chunk of rust that lodged itself between the thermostat and the housing allowing water to bypass it. Anyways, its gone now!
Baby viff is put back together now. Just have to wait to take it for a ride and see if it heats up. If not, its time to start blocking the radiator.