[Jeff Lee]

Back in the late '70's, a buddy Dean had a '69 Swinger 340 4-speed & 3.91's. Bone stock with bias ply tires. He worked the distributor and jetting. Shimmed the factory rockers. It was a consistent 14.00 car and ran in the 13.90's on a cool day with good barometric pressure.
He also had a '70 440-6 Road Runner with 727 and 4.10's. Same story on that car. He got it down to 13.40's on bias ply tires.
You should have seen the acid dipped, major lightening on every component '64 Signet he had with a 340 & 4-speed! It was a former street racer and my buddy Dean had a stock '69 340 with fender-well headers, 4-speed and 4.56's's in it. That ran 11.70 as I recall. A warmed over 340 (w-2 heads on a stock short-block, Purple Shaft cam, Torker). I think that ran 10.70's.
Car was feather light!
He would have loved Pure Stock racing but it wasn't around then.