If your only needing to pick up .15, you might try borrowing an alcohol carb from someone (one that is a known good working carb)

Alcohol has more impact on lower compression motors than high compression motors. On my wife's 11:1 motor is picked it up almost .3 and that was on a 390" small block with an out of the box Holley HP 950 alcohol carb from a 750 Barry Grant Silver Claw carb.

That may be the simplest, cheapest and quickest way to get you to 7.0 and if you can borrow one and try it first you can find out for sure without spending any money..