[Panoz60]

normally I dont drain the cooler unless I suspect the chance of debris in the oil. If you do, I would strongly suggest priming the motor afterwards. that can be done with an oil pump drive (removing the distributor and using a drill to drive the pump) or simply spinning the motor for 30-45 seconds with ignition off. you'd be suprised how long it takes to get all the air out of the lines and cooler.