Couple things I've done to fine tune with point weight with carbons and aluminums. Small brass washers behind the broadhead; I believe 3 rivers sells them in 5 & 10 grain increments.
Also, something else I've just recently done to get my judos to match my broadheads was fill the hollow center of a broadhead adapter with lead shot prior to glue up. This added 10-15 grains, though i'm sure that would vary depending on the size shot. You could also just fill it with molten lead for a little more.