360 Advice Needed - Autocross / Street Engine Build

I would get some 68-70 340 HP ex manifolds or some '92/early '93 magnum ex manis (they have ~2&5/16" outlets). the 360 ones are extremely restricted (check the outlet dia & you will see). I would keep (or get) the right cam & use octane booster as needed (add some in & proportion the % down to meet what the eng wants), no pinging allowed EVER.