If you haven't purchased the air gap already, then don't. Get a regular RPM intake instead, as it will have much better street manors, especially in the cooler months.
Same for the carb. Get a holley 3310 750 instead if you haven't purchased the 670 yet.
Plus the 3310 and the regular rpm will be much cheaper.
100 shot should not be a problem. Retard the timing a few degrees and make sure the n02 system has a separate fuel pump. Setup the activation switch for full throttle.
On my n02 setup, I used a 1 gallon fuel cell mounted in front of the radiator and ran racing fuel for the n02 fuel enrichment. Just an idea.
Your 383 should make 400hp and close to 500 ftlbs of torque.