72 340 build vs...other options

toolmanmike said
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.

Dartswinger70 said
Ah the cam, makes sense in the smog era.- Yes I believe the later 340s... the smog era killed them its actually a shame. But the 340 I beleive is easily moddable for the racer working at home the parts interchangeability I like the full floating pistons makes piston swaps easy etc.

You two guys above, the low compression years of the 340 and all the HP 4bbl 360 engines (IIRC) used the same early 340.

350’s could be had with a smaller 2bbl cam and a 4bbl.

65 Cuda 340 said
318 net hp is 150. Going from gross to net, they lost 80 hp (rated, not actual) with the same compression, carb, etc. as it had before. The 340 went from 275 supposedly gross to 240 net after losing two full points of CR, getting smaller exhaust valve and (at least compared to 68-70) worse passenger side exhaust manifold. That's less loss (on paper) than any big block that lost the same amount of CR. Actually, I've always thought the early 340 275 hp rating was net from the git go.

BUT - a 360 has 20 more cubes. And it's easier and cheaper to find one. If I'm rebuilding the motor anyway and didn't already have a 340, I'd look for a 360. Since I do have a virgin 340 block, if I build one more motor before I croak, it will be the 340 - but with a stroker crank, so the 20 less cubes in original form won't matter.

The exhaust valves for the 340 & 360 are and have always been a 1.60. The intakes for the later 340’s and all 360’s are the 1.88’s.
Is that what you meant?