Valvetrain noise - Magnum headed LA 360

I did the swap with the same thin Mopar head gaskets. The cam was already in before the swap with Rhoads lifters. After the swap, the lifters were noisy to the point that it sounded like the rocker arms were loose. I checked preload and it was roughly .040". I swapped to regular lifters, measured roughly the same preload and things quieted down substantially. I would double check the rocker arms and make sure they are still torqued down properly. Some noise is to be expected, or so I am told, with the newer performance cams.