A lot has to do with not only the tire but the suspension, launch rpm, how well the clutch is acting, carb jetting, etc...
I met a number of fellas running that MP create 360/380. I don't remember seeing a 4spd car though. There et's varied due to car weight and how serious they were about running the car.
Full interior guys were upper 12's & mostly strip cars were low 12's. A few guys ran into the 11's with a gutted light weight Duster. I really don't know how far they went to achieve that goal. But the interior was super spartan.
