There can never be a direct factory compare of a low compression 2bbl 318 to a high compression 4bbl 340. Even the Police 318 4bbl was choked by huge chambered 360 heads and a piston half way down to china in the bore.
But if you took a 273 4bbl 10.25 CR and its horsepower to cube ratio and directly did the math of the 43 extra cubes it comes close to 273 HP for a 318. So put 10.25 CR pistons in a 318 block for a near 0 deck, put a 360 head with its 1.88 valves, a 340 resto cam, 4bbl intake, 625 CFM AFB and 5.9 magnum exhaust manifolds on it then it should pump out close to the same ratio.
But the 340 Cult will never agree.
