I am trying to figure out my valve train noise. I have a 340 with a Hughes 1928 cam hydraulic. I used the stock rockers and with the stock push rods and had a lot of lifter noise so they said I probably needed a longer push rod due to the difference of the base circle. I need to figure out how to set the preload. Anyone have some suggestions. When I set them where I think they should be there is no compression, ie valve opened. Thanks in advance. Mike