I just got done doing a valve adjustment on my 350. It has hydraulic lifters. I looked around and ended up going with the method on hotrodders.com. Here's the link: http://www.hotrodders.com/forum/best-way-adjusting-valves-sbc-132599.html post #6 by "Frisco". I've had it in the car and running fairly decent for about 6 months now. I've probably driven it around 30 or so miles total. But it ran pretty good. I noticed what I thought was excessive valvetrain noise, so I figured I'd go through and make sure all the valves were good. Going with this method, they all needed to be cinched down a little. After the adjustment, it won't run. It turns, but it doesn't fire at all. All I did was take the slack out of each valve in the described method from that post. What might have gone wrong?