I just did the same thing on my Grand Cherokee...even broke a bit off in the bolt...I tried using the "heavy dudy" bits from autozone...titanium or whatever and they wouldn't do anything at all, just broke because of heat/flex...pulled the intake today. Luckily, i've found some used intakes for around $50, so i'm not sure if it would be worth it for me to pay a machine shop to get the bolt out and retap or just use a diff. intake. Either way, good luck, i know how you feel 
