318 piston's and quench

getting quench will be major $$$ if its an open chambered heads as the recessed area needs to be machined flat/uniform (they tend not to be as cast) plus quench dome pistons ($$$) & they need machined after mockup/measureing to get the .030-.035" piston to head clearance you are after. With closed chambered heads you'll still need quench dome pistons ($$$) plus mockup/machining. you can get a set of 30 over 318 pistons on eBay for slightly over $100 & you wont have quench so you lose some efficiency but it'll be a much cheaper build. may I ask why you are set on a 318 expecially since you do not have the block. I'd go with a 360 but more info on what you have in mind