build a 360! & stroker cranks are dirt cheap now (Hughes has em on sale). I'm doing one & I might be able to mill the OE cast 360 pistons. just need to mockup & see where I'm at & a cometic custom thick gasket is an option around this also if it comes to that & if not, stroker pistons ain't that costly. After you feel that power the numbers matching 318 sitting in your garage will be the last thing on your mind.