360 engine vibration

Its on fresh fuel, bought 2 weeks ago. tank has been replaced ( replaced in USA at some point). has new glass fuel filter ( never seen any dirt in it) and I think pump changed as I have old spare in boot (trunk).
As an observation I didnt think the rockers lifted much when turning over by hand. In fact the when the rocker rail was removed the pushrods are pretty much at an even height plus or minus 3/8" I was expecting a bigger difference as per other engines im used to?

2 x cans of sea foam ordered