67 GTO. Pontiac 400, .030 over stroked to a 461.
I hand turned the engine until the exhaust valve started to open, then set the intake lash, I started with 1/2 turn lash. Then turned the crank until intake valve started to open, then set the exhaust lash. I did one cylinder at a time, or in a sense one valve at a time. The valve covers were rattling something bad, so then I tried them at 3/4 lash. The engine shook in the bay a bit, so I dropped it down till about a 1/3 lash. Smoother running but a bit of a choppy idle.
I'm thinking maybe something is off with the mechanical timing....
What happens if the cam is in fact degree correctly, but the timing gear on the cam is off a small bit, say one or two teeth?