Thanks for sharing but to answer your question sometimes 415 HP just isn't enough and the old addage that there is no substitute for cubic inches stills hold true. The 318 is a good engine, at .060 over it's just a pubic hair shy of a 4.00" bore. Not enough to really make difference there and if you want to stroke it 390+ cubes are possible.
Otherwise with it's short stroke it can be a high revving piece like the 340. I've thought many times about building a smaller cube version of my previous 340 because I loved that 8000+ RPM on the top end but now that everything is 1/8 mile around here it wouldn't be a good combo.