I know it isn't a Buick engine but it may help another Buick guy. A young lady (30 or so?) getting into the hot rod scene has a stock bottom end 350 Chevy, mild cam, stock exhaust manifolds, Edelbrock 1407 on a dual plane intake and HEI that is currently running 10 degrees initial and something like 28 all in by 3500. It's transplanted into a '48 Chevy pickup with a T-350 automatic. High 3 series gears. She describes the problem as a light pinging at 2200 - 3000 rpm with any additional advance in the distributor, nothing before that or after. She also said that it was worse before a metering rod change and backing down the timing. My advice to her was try two to four jets sizes bigger, a selection of metering rods and switching the vacuum source between manifold and ported to see which gives the best in driveability. Any other suggestions? A new carburetor isn't an option, budgets you know?