273 or NOT 273?
Remember, the 318 2 barrel is close to or better than a 273-4 barrel and at lower rpm's. Who wouldn't want 80 lb/ft more torque at 2400 rpm where most of us spend the majority of our time.
273-4 235 hp@5200 rpm 260 lb/ft @4000 rpm
318-2 230 hp@4400 rpm 340 lb/ft @2400 rpm