Oh crap, I forgot since it's adamant it won't be equal. Well I just did a quick calc and I think this is what will happen
adamant nature tyrouge at level 20 is 27 attack
For it to be equal, it needs to get 36~55 def EVs.
I can erase them later so that won't be a problem. Maybe just save before training/EVing/rare candying it just in case i messed up my calculations. Also in gen4, EVs don't get added until it levels unlike in B/W
Sorry, didn't know this was going to be so difficult T.T I'll definently help you with any future BP/CP so dw