Double check those timing suggestions
34 was what I ran for X-J heads
The late heads, magnums and the Aluminum may take much less (which is good)
what cam did you end up with
did you post a recent compression check? get the carb sorted out?
And they might like more. I have seen several eddie combo’s that ran best at 40. Saw B1BA aluminum heads that like 40 as well
My w5 heads ran best at 32. Its more chamber/combo
specific than anything else. Not the material.