Broken intake bolts in my heads

[94blackgt 1621]

I was removing my intake bolts and 2 of the bolts snapped off and are now stuck into my heads. i tried the easy out way, but the cheap pieces of crap kept braking. now im going to drill the old bolt out and retap the hole, the bolt size that goes into the hole is a 5/16-18. but what i dont know is what drill bit i should use to get that old bolt out that will be small enough to still let me put threads in the new hole. anyone know?

chad

 

[battyice]

I would purchase a 5/16" Heli-coil kit. The kit will come with the correct size drill bit to allow you to drill out those old intake bolts, and insert the new threads.