There's so many false assertion here don't even know where to start. Why do you insist on shitting on everyone that wants to build a 318, we get it you don't think there a good platform to build power from.
Does a Smaller engine generally make less power at similar rpms (powerband) as a larger engine yes and everyone knows that, if you want a smaller to make similar power as the larger engine it got to spin higher basically the cid percentage difference and or be more efficient. If the OP is fine with that why can't you guys?
The dudes engine is only 17 cid (5%) smaller than a 340 it's gonna behave similar.