Gatorac,
It sounds like you have tried just about everything. But, you might want to start over, drain/flush the whole system, put a 160 thermostat in, a proper water/
antifreeze mix and run it. This may solve your problem. Something might be restricting the flow of coolant and flushing it out might help? I would have suggested checking your gauge, but apparently you have already done so. LIke Cashburn, I also suspect some trapped air in the system. Let it run without the cap on until hot and add coolant if the level drops. BTW, is there any coolant in the "puke tank"?