A couple suggestions I have on whatever motor you choose. The big key in my opinion of any motor is in the heads. Not necisarely big runner volume either( just efficant). Do yor research a simple head swap can up compression and flow. around 10 to 1 compression. A mild cam around 220 /230 duration or Smaller. Dual plane intake and headers. 300 -350 hp should be easy to obtaine on most gm v8.i like torqu over hp on the street. Pick a cam that's peak rpm is 6000 or less. If you outline what you want on paper first(to keep you on track). Do research, hit up swap meets and be patient. You don't have to spend a fortune. To have a fun car.