i just adjusted valve lash and changed the plugs on my chevy350. its a brand new engine and the compression was a little shakey so i did a valve lash adjustment... i swear i followed the book to a "t" and when i put everything back there is no compression anywhere. i can feel air while cranking the engine just out side the spark plug holes but no compression! i did it again hoping i could correct the first mistake but same results again! has anyone heard of this? any suggestions on what i did wrong? thanks, sawbones.