I have a 1970 cadillac with a 455 pontiac motor in it. stock short block & rotating assembly, large cam, high rise intake manifold ported and polished matching the ported and polished 6x heads, roller rockers, hei distributor, electric feul pump, demon 850 carb with no choke on it. currently the vacuum secondaries are not working . i am having pining issues under aggressive acceleration, backed down the timing a bit, tried increasing the fuel, still pining. will higher octane (100+) solve this, or could it be the secondaries not opening when needed?