roccodart440 what kind of cam and rocker ratio are you running and what lift does it make at the valves? Also what's your gearing and converter stall like? Not to mention what's your elevation where you live if you happen to know? 242* @.050" is on the upper end of durations I'm considering because like I said the thin air up here in the mountains lowers the dynamic compression ratio a significant amount; a cam that would work well with 10.5:1 static compression around sea level might lose enough low-end torque to be sluggish at high altitude.
Just to give you an idea my current engine/drivetrain combo should be good for mid-high 13's at sea level. BUT up here at Bandimere Speedway my best run so far has been a 14.9 @ 96.4 MPH. Cars running 13's at this altitude are built up much more than mine thus would be running in the 11-12 second range at sea level.
It's a real bummer when you're racing guys with blowers/turbos the difference to N/A is drastic with the thin air. For sure my next major engine project will be to rebuild my old 318 into a turbo engine and make an easy 500 HP.