As for the timing retard get a digtel 6 plus and hook the retard wire to the nos button or trans break button to pull timing when nos is turned on. You may not need to pull timing on a 100 shot but it is better to be safe then sorry.

If jetting on car is already good do not mess with it.As far as what plugs should look like on a nos tune go to induction solutions web site , steve has a place where guys send pics of plugs in and he tells them what is going on.

Make sure your fuel pump is large enough to support both systems. we run a 500 with 2 regulators one for motor and one for nos tune.