Any fast 318s out there?

They respond like any other engine. Build for performance, get some real compression in it, add decent heads and cam, and off you go. They are basically identical to a 340 minus the reputation and 2.75 cubic inches of bore per cylinder. Yes, you can gvet forged pistons for them, but be aware that you need to have the block square decked t the proper height to get the compression up where it needs to be. Nothing really fancy needs to be done.