I know they will work there has been alot of people on here that have done it and i have talked to people at car shows that have also done it. Each hole has to be 1/4" longer. there are post of people saying it works great but not sure how they are boring the hole out bigger.
send it to a machine shop or a freind with a mill. thats some heavy duty stuff to just grind thru... unless u torch the holes and then clean them with a grinder....