440 into a /6 duster

Maybe its because its my first swap but I spend all weekend with 3 other people trying to get things changed and all i have right now is a 440 with a 727 bolted in...no headers or rear put back in yet. Granted I the taller TrickFlow heads I'm using and the fact the car was a factory AC car are probably causing problems as well. Spent the good part of a day beating the passenger side valve cover down and grinding on the rocker shaft hold downs in order for the motor to "clear" the blower motor. I say "clear" but I unscrewed the blower motor and moved it to the side...it still hits the valve cover.