broSSartweld

My rx7 has been overheating when I climb hills but the temp guage reads fine on level ground driving. I just removed the aftermarket radiator I had in and installed a factory aluminum model. I hope that solves the problem. I have replaced just about all cooling components searching for the cause of this problem.I was just underneath and found a small amount of coolant dripping from the area where the engine is bolted to the manual gearbox(flywheel access rubber plug area). I have also pressure tested the system and has a very slow bleed down in pressure. I have the regular belt driven fan. Do i need an auxillary electric fan, do rx7's run hot? Anybody have any suggestions?