I had mine drilled and tapped with a Weaver 93 Base. It uses 4 holes, as I was worried about the aluminum receiver and strength.
I also had it mounted farther forward, as I wanted the EoTech to be farther away from my face for visibility.
It does cost more for 4 holes to be drilled, as most gunsmith charge per hole drilled.
I'm happy so far.
God Bless,
David B.