when you put on the zex kit all you have the do is make sure you retard timing 2 degrees for a 65 shot and also get colder spark plugs and gap them smaller Or just use the zex triple electrode plugs. i use them on my turbo car
make sure you installed the nozzle at least 12-14 inches away from the throttle body so the nitrous can flow evenly through the engine.
leave the cam sprockets alone. if you touch them, make sure its on a dyno

good luck