I am replacing old 1.6 ratio rocker arms with new 1.5 roller rockers. I also bought stock length ball and cup push rods for my new roller rocker set up. My heads have been decked so they are a little shorter than stock but my old stock set up worked ok after the rebuild. I got my new rocker arms and pushrods on but there is preload on the valves even though my adjustment screws are backed all the way off. Is it normal practice to buy shorter push rods when installing roller rockers? By the way, my engine is a 69 dodge 440.