just to be clear though - the honey isn't going to lower the final gravity of what you would get if you don't add any honey since you have already made the wort and are not replacing malt with honey. it increases the OG, but since honey will ferment all the way down, you can get to the same OG.
so if your 1.070 malt only IPA had 80% attenuation, you'd finish around 1.014. If you add a lb of honey, your OG should go up to ~1.078, but you should still finish at 1.014.