Threads pulled in block, help please?

I was torqueing my arp studs while mounting my AFR 185's and when I got to the third bolt I felt the threads give way. The threads are toast. After I got through throwing up I figured I could make a nice drill guide at work and install a heli-coil in this hole. Tell me if this is a good idea or if there are better options at this point. I would really rather not take the engine back to the shop just to have them heli-coil it. I can make up a nice jig at work (toolmaker) and either install a heli-coil or drill to next size I guess. What does everyone think? Oh and can someone give me the spread between the holes on the block or a site that has the block dimensions?

Thanks man, I gotta be due for a break on this build up. I am having the hardest time getting this thing back on the road. I have way too much time and money in this to let one bolt hole stop me. Please does anyone have the dimensions I need? otherwise its off to work to get my micrometers then the 30 minute drive where my car is being stored and then back to work to get started on a drill guide jig.....