Another idea just popped in... You said that it is a full roller set up. Was that hydraulic lifters? Used to with hydraulic, you take it to zero lash and then another 3/4 turn down. When doing my 383 which is hydraulic, they are adjusted 1/8 turn from zero lash. IF you did the old 3/4 turn, it could match up with an earlier idea about intake being open too long....
Oops I delayed 30 seconds, bet Aussie (or someone else) sends this before I do...
