Its getting better but still wrong.

[mrsmothers]

Well I got my 50 on the road runs pretty good. I set the valves the other day while it was idling and got them all nice and quite. When I get in to 3rd gear you can hear a rattling , if i get to far up on my rpms it back fires. Also keeps blowing the pcv valve out of the valve cover. its a 350 btw.

So the question is why is it doing this? valve to tight, valve to loose, timing off?
should I re adjust the valves at higher rpm?