Destroking an Engine

They where back in 70's in Modified production class , for a example I had 1966 chevelle that ran ran F/MP and we where only able to have so much cubic inch to weight. I ran 301 cu in small block a 327 with 283 crank. Now I launched it @9000 rpms had 50lb flywheel and 6:17 gears with a 3.31 first gear in a 4 speed trans.