i had the same problem, also used the jc whittny bulbs, but that does not do the trick. I put 2 relay switchs in line, one for the high beam 1 for low beam. I toke a hot wire right of the altenator to the relay swithes then spliced the into the headlight wires, thus no voltage drop that you get from the power going through the dash and light switch. Works great, I now have all the power and more. Even on low beam I still get people giving the bright lights. Don't forget to put in a fuse between the altenater and the relay swithes. It worked for me.
Dave.