I put a .474/280 MP cam in a stock 318. That is for sure larger than a 340 cam. I put a TQ on top. It was faster. I won races. Even with my stock TC and 2.76 gears.
thats the hemi grind isn't it? i had that cam in a 69-70 stock 318 many years ago,, i forget if i had the J heads on that motor or not. had 3.23 gears in it, small eddy carb and headers.. car ran damn well... idled and drove stockish.