I have my 79 350 with 416 heads. I have a cam with .470 lift. I adjusted the preload on #1 and turned it to goto the next cylinder. Then the motor stopped turning and I could feel the bolt turning inside. so instead of pushing the issue I stopped and loosed the rockers again. I turned it over with the starter and it turns easily now. I have the spark plugs out so it's not the compression. Was I making constact with the pistions with .470 lift?