if i tune my supercharger v6 stang with an sct excalibrator n dino with 24 injectors, when i put the 42 injectors do i have to do it all again or can i just change the settings of injector size in the sct, n if i change to 42 do i have to mod anything in the engine, dont want to blow it.

 

I would wait to dyno tune with the larger injectors, and use the handheld to get a basic tune until that point. Just don't rag on it too much until you get it tuned well.