Originally Posted by xbgs351
What is the minimum recomended piston/head clearance for a 351 cleveland, factory crank, 302 rods, hypatec hypereutectic pistons and a 6500 rpm shift point?
Unless you have domed pistons, you probably won't have a clearance problem. What you need to check is more likely going to be piston to valve clearance or simply P-V. If you were building a "chamber follower" piston trying to eek out the most possible compression, you'd want to leave at least the thermal expansion characteristics of your pistons. I've never built an engine with anything but forged pistons, so I can't say what that dimension is for your pistons. Then you'd want to add a bit, say 8-10 thousandths to be safe. You'll probably want to have a total of about .045-.055" clearance, but please check with the piston manufacturer and don't take my word for it. Here is a link to a site that says that .040"-.045" quench distance works best.
Note that if you use a .040" compressed head gasket, that you should be very close to or at zero deck. My 393, for example, has what are basically aluminum copies (A3 cylinder heads) of the factory 4V CC combustion chambers. I didn't find any way that they are really very different except for a bit more space around the valves, but they were also right at 66cc, too! My pistons are .008" below zero with a .040" gasket giving .048" quench.
However, you're more likely to find that you have plenty of clearance around the piston in everywhere but the valves. Checking your P-V you'll want to maintain at least .100" with a solid lifter cam and .125" with a hydraulic lifter cam.
You probably have flat tops with dual valve reliefs...just guessing (and not familiar at all with Aussie 302C rods/351C piston choices). Be sure to use the recommended springs for your camshaft and ensure that they are installed to the correct installed height as listed for proper spring open/closed pressures.