Old US muscle cars are generally underrated, and measured at the wheel.
There are quite a few rules in the stock car class, and these naturally aspirated V8's most definitely broke that 545 HP mark.
Your 4WD is nice but adds weight with the added drivetrain parts. RWD is the only way to go for a quarter mile car.
Now I could be wrong, but I always thought that saying "10 second car" meant breaking 10 seconds. Not breaking 11 seconds...