body panels of 924

i own a 79 924, i was wondering if it's possible to take fenders or doors or a hood or any body panels off a 924s and put them on the 79, they look the same but i might be missing something, and does anyone make new engines or rebuilt ones, i've got money to spend, and the porsche is the car i have that needs it. and does it take premium or regular, my manual got screwed up, damn cats. i bought the car from a salvage yard, and never drove it, tried but it needs a valve job badly