2004 POntiac Grand Am 3.4L Overheating/losing coolant

2004 Pontiac Grand Am. Overheating and losing coolant. I've replaced the water pump, thermostat, temp sensor, and overflow reservoir. I've bypassed the heater core and still same problem. When starting from cold the temp spikes to about 230-240 before it goes back to normal operating temp of 200-ish. If I let it idle to temp it runs fine after the initial temp spike, and if I drive from cold it spikes at 260 (with warning light) and starts to lose fluid through the reservoir, then it runs fine. I had it pressure tested, and I do have a small leak in the gasket (thanks Dex-cool), but no other signs of a blown gasket. No white smoke or coolant smell in the cabin. No coolant in the oil. Fans are working as they should. Once it's up and running at normal operating temp I do not lose fluid. No puddles under while parked. The hoses are a bit soft, but otherwise in good shape. I also have a misfire trouble code, but not sure if that is related or just needs a tune-up. I'd hate to put $1000's into replacing the gasket and heater core and worry that still may not solve the problem.