[bigblockv6]

I've cut quite a few of these clusters for back mounting and the way they were designed it didn't even require using a hole saw. I did one right at one of our mini meets in 2004 at Brooks Oregon on Sam Roes truck. I drilled a hole big enough to fit a hacksaw blade then cut 3 slits in the plastic and broke them off, it tends to break right at the perforated chrome circle that establishes the proper hole size followed with some 40 & 80 grit sandpaper to finish the holes edges. If you want more chrome to show then it will require using a bigger hole saw and that's where it becomes really critical to be right on center with drilling.