Projects 29 A Roadster,32 rails, SBC

I need to relieve my firewall somewhat for a turbo 350. To those of you that have done this before, it seems to me that the original firewall recess lines up real well with the sbc dizzy. Do you agree or have you moved yours toward the drivers side for more symmetry. This may be a really simple question, but I just don't want to do any unnecessary carving that I have to come back and repair. Thanks , Bill