warped head you will need a head job .....Install a pressure tester on the radiator if it goes from 0- 35 or more you need a head job. If it holds at 15 or less your ok. But I wont be surprise if it shoots to 35 or more. You can also take the radiator cap off when called. Fill it with water only and when it's full crank it up and rev it at 3-4k rpms and see if it shoots a roaster tail out of the radiator. If it starts spitting the fluid out you need a head job.