I did a black IPA with
3% Carafa Special II
2% Pale Choclate
I mashed the dark malts - the malt backbone was right for the IBUs but too bitter/roasty for my taste. If I made this again I would steep, not mash, the dark malts and add the liquid to the boil.
I'd drop the Carafa Special II and up the Chocolate to 5%. Sure, it'll be and American Brown but it won't have that roasty character that doesn't go at all well with citrus hops. Just an opinion from of a guy that hasn't found a Black IPA he likes.