What spark plugs to run [nitrous setup]? how do change timing?

hey am not trying to hijack your forum but am going to be spraying the car soon am just wondering is it possible to spray the car lets say dry 50 shot or something without changing timming??

and silver gt not sure if you need it for a stang or not but i came across this incase some one needs it
http://www.mustangforums.com/m_1299690/tm.htm