PA Hillclimb

I was wondering where the rules would be found for these classes?
Also ITE? I am trying to help a friend class an early WRX that is prepped beyond SM specs, mainly because full gut, some subframe replacement, and some other minor changes.

Generally, SPO and SPU follow Production/GT safety rules. Nediv SCCA website has the class rules. Could the car be classed as a ST car, as STU or STO in GT-2? ITE was supposed to be for old World Challenge/ Continental Tire race cars.

Thanks for the info rich. ITE may still be the best fit as this is a street driven car.