You will need something to reseal the IC tubes when you go back together. You can use copper RTV, or Tbird88 makes reuseable teflon gaskets for about $20.
While you have the IC out clean all the oil out of it. Use mineral spirits.
After you replace everything you will need to purge all the air from the system or you will end up overheating and blowing a headgasket. Here is something from an earlier post.
“You’re probably low on coolant. In these cars the upper rad hose is higher than the rest of the system and is hard to get all the air purged from the system. Look to the right of the thermostat housing (Where the upper rad hose attaches to), there is a bolt with a plastic cap on it. Remove the bolt (use a backup wrench on the tube or you might twist the tube). Remove the rad cap and fill until coolant comes out from the tube (Be sure to rinse the front of the engine down because the coolant can cause the crank position sensor to fail, I don't know why since it is a magnetic hall effect switch, but it does).
Make sure the rad cap is good (if you have the slightest doubt replace it). Make sure the coolant overflow holds coolant and doesn't leak, or it will do it again. Run the engine, drive around the block a few times and shut the engine off. Do this a few times. The object is to allow the cooling system to pressurize and then cool. The expansion and contraction will expel the air and suck in coolant to replace the area occupied by the air. After things are working properly then only coolant will pass back and forth between the overflow and rad.”
Jeff
