After finally finding the PO I'm told the engine in my pickup is a 1971 350 block with a 283 crank making it a 302. My truck was running fine prior to adjusting the valves. I was trying to get rid of a little clatter a couple valves had. I was trying to adjust the valves that I'm assuming are hydraulic by loosening the nut until it clatters, tighten until the clutter stops plus 1/4 more. Just will not run right. I have tried 1/2 more after the clatter stops but it runs worse. I was thinking they may be solid lifters but was told it probably would not have ran tightening the valves down that much. Looking for a little help.