Dead stock bottom end quickness

73 duster with a 68 383 only changed the camshaft and intake. The camshaft was a 284 / .480 trw bought at the local Big A auto parts. The intake was a edelbrock performer with a 750 holley dp. The car was a dailey driver 3400lbs plus with the tool box in the trunk, it had 3.91 gears with pro trac 60's. Ran 8.00 1/8 th mile.