the unfortunate fact is if it still runs good the head may be cracked, generally when the gasket blows it goes big and effects the running, before you tear it apart check the pisser line from the right side (as you are looking at it) of the radiator for free flowing coolant into the bottle as you rev it with the cap off, no squirt into the bottle it's, A, low on coolant, B, clogged, C, no coolant flow due to stuck closed thermostat or busted plastic impeller water pump (these will make it overheat fast) plastic water pumps are getting rare but they still show up occasionally, the best test i've found for a cracked head requires a air compressor and a compression tester with the air coupler type connection so you can hook it to a air hose, remove the schrader valve from the compression tester so you can blow though it, fill the cooling system to the top and start pressurizing the cylinders, you will need to roll the engine over and hold it when you feel/hear it holding the pressure when both valves are closed, watch for the coolant rising, if you do all 6 and get no burp the gasket/head is most likely fine
quick tip to make filling the cooling system easier is to drill a small hole where the arrow is on the thermostat before you install it and put it straight up at the 12:00 position, around 1/8" will do
all america wants is cold beer warm cat and a place to take a poop with a door on it