Well, I went to fire up my "new" 455 and it won't start. I've got gas and spark but no compression. Thankfully I didn't turn her over very much to figure out that I had no compression. It didn't sound right as it spun over. No S$%^ - right!!!! Anyway, I figure I messed up adjusting the valves. I did em when the valley pan was still off so I just looked at the cam and adjusted them when on lowest spot. Took the slack out and went 1/2 turn. Then I would turn motor over by hand and do the next one, right down the line. I don't see how I could've messed that up, but I'm pretty sure I did. Oh well, next weekend maybe it'll run!!!! Glad I didn't seal those valve covers yet. Wanted to get it running and then seal em. I'll look on here for another method. This time with the valley pan on and looking at the rockers. Suggestions, or does it sound like I am on the right track?