KB 191's in my 360

Sorry but this gets wordy...To get the total benefit of the quench effect, there's a lot of work to be done. The chamber is sand cast and not that well... What that means is depth of each chamber, and shape, and the height of the surface features are all different chamber to chamber. The way to get proper quench distance regardless of head or piston is to first align hone the mains, then square deck the block (indexing the deck height to the now perfect crank centerline). Then the crank and rods need to be checked for stroke length and rod center to center length. These commonly vary from exactly the same to blueprint spec plus or minus up to .010 each. I've seen strokes off .008, and rod lengths in the same set .010 different from longest to shortest. You have to have every hole the same. When that;s done, you mock up the short and clay all eight holes. You do that to get the deepest chamber. Then you make all the chambers the same size, usually by polishing the flat where the piston's quench pad comes up close to. Once they are equal and flat, you mill the head to get the quench distance correct. It has to be less than .050", and the tighter it is the more effective it is against detonation. I typically set this between .030 and .040, depending on the bore size and piston compression height. On a 360, I'd be looking at setting it at .030. Once the heads are milled, you can use the formula to mill the intake flange side to allow the intake to fit and you're done. It is MUCH easier to just do the first and second parts (square decking and stroke indexing and length matching) because they are part of the normal blueprinting steps. The rest is repeated on and off with the heads, and a lot more hand labor. Those pistons are designed to have the dome trimmed to achieve the proper quench, but you still have the issue of differring chamber depths which as I said could mena your quench would be either too wide, or too close depending on which chamber you use to calculate the thickness of material to be removed from the piston. this might be why they are for sale cheap...