This is my first mustang so im not sure. i was juss wondering if the engine getting pretty close to hot but still within the normal dashes is normal. like normal idling its between the r and m in normal but with the ac on in traffic goes almost close to l...is this normal? n my ac blew out yesturday when i was parking all the freon came out gotta check the leak. thanks for the help...oh yea opne more thing is it hard to replace the heater core in a 97?