im in the process of doing the heads and as previously posted, i stripped a head bolt. i bought the helicoil kit to repair the threads. the service manual says that i need the drill the threads to 31/64". i went to lowes and bought a 31/64" bit but its only 6" long, and i doubt its able to reach the threads. i also bought a 1/2" bit that is 1' long. would i be able to use the 1/2" bit to drill out the threads or is that 1/64" gonna cause some damage????