Disclosure: I am an inspection mechanic

PennDOT says that any registered and insured vehicle that will be operated in the state may be inspected. Even with a temporary tag. Even if that temporary tag is issued by another state or even country.

You may even present the vehicle for inspection without either of those things if you want. It will just be recorded in the logbook as a fail, you have to pay anyway, but can come back and have the sticker installed once you have the paperwork. I dont know why you would do this, but you can.