emissions and such

i searched for this numerous times both these forums and different search engines, but haven't found anything. i was just curious if anyone had any information on where to find the exact legal laws for car modifications in pennsylvania. i know sr20det's will pass smog and visuals. i just would like to read up on them to find exactly what i can and can't do to a car. thanks much appreciated.

you try dmv.pa.gov? or wherever your dmv website is?