I wouldn't even try to drill out a broken tap ( you would need a cobalt bit, and even then the broken tap would break up in chunks) Use a broken tap extractor:

 

The aluminum castings are way softer than the hardened steel tap. I guarantee you will not snap it off in the aluminum if you continually back the tap out after going forward clockwise a few revolutions. In other words don`t make a straight run without backing the tool out every so often

 

Mike, no joke, are you considering offering your services to us less inclined? I'd like to take a # and get in line : )

 

Hi Kenny, no unfortunately I am not offering my services, but like I said, it is pretty easy, you just have to be prepared to do this over a 2 day period and not push it. Between Steves post on rennlist and mine here,,,you can do it. Otherwise Sharkworks can do it for you, Mike

 

those are awesome who makes em?

 

I'm trying to figure out how you got the right side by the oil tank. Can you explain that please