CDM mount-point dimension

[sataraid1]

Is the precise measurement for a CDM 1250 across the bracket mounting points published somewhere? My calipers are too small, and I haven't been able to find the dimension listed in any of the service manuals. Rather than buying a new caliper, or hauling the radio to a shop, could someone look it up or take a measurement for me?

I'm having a custom bracket built, and don't want to risk ruining a prototype by trying to eyeball it with a ruler or coming up with some other half-baked means of measurement.

My best guesstimate at the moment is 6 5/8".

As always, thanks in advance.