72 340 build vs...other options

The Later 340's lack compression, cam, and cylinder head. The stockers have more restrictive exhaust manifolds. I'm sure there are differences in distributor timing, carbruation and intake as well. The 73's did have electronic ignition and Thermoquad carbs which can be a plus. 240 net horsepower. the 318's made 230 horse up till 71. Net horsepower ratings started in 71 I believe so there's that.