Today, dollar for dollar, is the 318 faster than the 340 ???

Well
Not saying it would, I have a feeling It would make 400 hp, Just keep seeing a 318 is gonna need $$$$$ to get their I'm saying if It needs a different cam thats not gonna cost anymore at worst if It needs more CR to reach it that will cost a bit but nothing crazy, not seeing where all these extra dollars are gonna come from?? Peeps are acting like your gonna need fully port W2 with 15:1 and a huge solid roller or something :)
If you change pistons you will have to get the bottom end rebalanced

The 400hp 318 will run as good as you can set your chassis up.