I have had good results adjusting Hyd lifters this way. Turn engine so #1 is TDC and both valves are closed. Adjust rockers until the push rod just stops turning with your fingers. Get both on #1. then look at all of the other valves. About 1/2 will be closed. Adjust them as well same way. Turn engine to #6 at TDC. The other valves will now be closed. Adjust them the same way. Start it. If it clacks a bit do not worry, it will get better in a bit. When it is fully warmed up and that will take a bit of time Do it all over again, but, turn 1/4 turn after the push rod stops. Should be OK. All the Hyd lifters I have tried to adjust with a full turn seem to be too tight. This seems to work for me. It should idle real smooth and be very quite when you are done. If there are other ways to do this, let us know. I still turn the idle way down and adjust while running but that takes some time and you need to have a very loose but stable pair of hands. I don't know how long I can still do it but it does tell you right quick if you go too far, idle gets lumpy fast. Some of these engines will idle as slow as 150 RPM. Amazing really. As far as what engine you have? There are folks on here that know way better than I do.
