Most of those cars ran 13's/14s out of the box before 1973 but one has to remember that was with skinny bias ply tires that wouldn't grip off the line also usually highway gears and only a three speed auto or 4 speed manual trans.
No 4 or 5 speed autos or 6 speed manual trannys in those days so in completely stock form most not only ate up time smoking the tires off the line they also never got out of second or third gear in the 1320 (1/4 mile).
Mopar in particular had very high gearing in a lot of their cars,roadrunners often had very high gearing NASCAR style.
They could top 150 mph with ease in 4th gear with a 2:82 rear end but that meant at the drag strip they barely got past second gear.
All you had to do back then with about any big block muscle car to go fast in the 1320 was to throw a set of 4:56 or 4:88 rear end gears in and add a set of traction bars & fat tires.
Bam! you are running 12's,now add a few bolt ons to the motor and you're in the 11's or high 10's.
A good running 383 magnum Roadrunner should spank a V-6 Camaro in the 1320,later years with the 400 smog motor were a mear shadow of the older cars but still should give it a run in a full 1320.
It would be playing catch up after the 1/8 mile though with the little Camaro being much quicker off the line.
I remember my first ride in a muscle car well,I was 14 and my friends older cousin took us for a ride in his brand new 1970 Roadrunner with a 383 4speed,that ride was etched into my brain forever lol!
Black Sabbath Paranoid was playing on the 8track tape player as he let out the clutch and did what seemed like an impossibly long almost never ending burn out in 1st gear then proceeded through 2nd,3rd & 4th gears to absolute terrifying speeds.
I knew right then and there I had to have a muscle car one day.

 

sounds like you hads fun man !!