I believe the 79 Nova originally had the intake manifold integral (part of) the cylinder head. If where you live does not have smog/emission checks it will probably be worthwhile to find a pre-1975 head with the separate intake manifold. The integrals tend to crack and have very limited performance potential. It might be worthwhile to find a complete earlier 250 to rebuild as that way you can take your time with the rebuild and still keep the car on the road.
