What is the lowest cranking supply voltage that you can get away with when using a MSD box?

I have asked the MSD techs and they have not given me an answer in two days, so I thought that I would ask the real experts.

I have only found one place on the web that mentions 10.5v, one mentions 9-12v, and another one says 10v is the lowest cranking supply voltage, so I want to make sure.

Thanks to all.


1970 YO7 A66 [Canadian Export] F8 Challenger
340 (Currently in shop for stroker assy.)