Valve Lash Adjustment

There should be absolutely no need to adjust the rocker arms if they were properly adjusted the first time. And as Johnny said hydraulic cams don't require any lash. Lash is clearance needed by solid cams. Hydraulic cams whether flat tappet or roller style require preloading the lifter. If things are wearing and your getting lash in the valvetrain that isn't good at all and should be thoroughly inspected immediately because something isn't right. If you run it you run the risk of causing a major problem. If I were you I think I'd call the engine builder and tell him what's happening.