318 #302 head timing question

With the fast burn 302 heads, you likely won't need more than 34* total timing by 3000rpm...you'll need to recurve the dizzy to limit it.

When the editors say they only had 30* total timing, you have to realize, the vacuum advance only works when there's "less" than 0" hg in the manifold...under WOT, there should not be any less than 0" because the throttle is open. Under a lighter load, you create lowered manifold pressure, ie, cruising down the boulevard, you may have 22" hg (and your total advance may be as high as 50* when the engine is low demand, high manifold vacuum), but when you mat the pedal, the manifold pressure goes "up" to 0" hg (and your dizzy reverts to mechanical only)

In other words, dyno runs are WOT flog events, vacuum advance is essentially non-functional, so the dizzy is operating purely on the mechanical advance (weights and springs)