All I can say is, that a buddy's cousin had a '69 SS396 Malibu that easily did 6 second 0-60 times. Watched him run it at the old US 30 (York) NHRA strip back then and it did pretty well. Usually best in class. IIRC it had the optional 375HP version 396, but knowing him it wasn't strictly "bone stock"? He took top stock eliminator with it at another track and lost on protest.
They dialed the cam. Lift/duration didn't quite meet specs.
Don't remember his 1/4 mile times at US30, but figure they were probably in the low 11 seconds bracket, or damn close?
I ran my '64 LeMans coupe there back then and turned low 14s. 326CI, four speed. Best thing I had going, was the hole shot and flawless shifts. Because whatever came in second, was usually only half a fender short? K/S, I think? Too long ago to remember.
BTW, this is what I've been driving for seven years: 355HP Silverado 1500 4x4. Ain't a slouch.
https://www.youtube.com/watch?v=loOSXOhutQg