Well if you wanted to add an extra safty margin, and more power by upping the boost, the alch injection would be the best way to go.

If you trust the motor and we al know you have a great tuner, the N2O would let you get that 11sec pass, but at what cost?

The ultamite way to go would to get both I would run a small shot35-50 and the alch kit and be set. 11's would be no problem, and detonation would be at the bottom of you list of worries.. either way you go, tune it on the safe side so that motor lives to see LOTS of 11sec passes, so you and me can take a few runs together.