That'll work. You'll be getting all your singal amplification from the V2 instead of making up gain in the AD2k, plus and metering on the V2 will be close and usable. The V2's meters will read 3dB higher than the a level hitting the ADC, so -3dBFS on the V2 should = cliping on the AD2k.
That's how the metering would work with the V3, I forget how the V2 meters work but imagine it's the same. I haven't used the AD2k, but if you use it's meters instead of the ones on the Grace, then the metering will accurately reflect the level to teh ADC without any mental conversion.