you can take it off as long as you have a good friend at your local inspection station, or someone that doesnt look. here in TX, the smog pump, even with a safety only inspection, must appear to be in solid working order. notice the word appear?? lots of people will do a few little tinkering type deals that pretty much renders the smog system inoperable but retains the stock working appearance.
doing away with the smog system on your truck will probably start throwing O2 sensor codes at you later on down the road.