lets revisit timing

A good curve for a 10:1 340 usually falls around 10 initial with another 24 mechanical for a total of about 34 at around 3000 rpm without vacuum advance which may add another 16 or so for a cruising total around 50.
how might the engine performance differ with totals of 30 - 36 at wot ( no vac adv.)
..would it be noticeable?