John: If the heart/pith is in the brace it's more likely to crack or check, as it's such a small timber and easier to air dry. If your braces have the dimension of 3 1/8" x 5", I wouldn't box the heart. My personal rule is to 'box heart' timbers starting at 5" thick and thicker, by 5" wide and wider both dimensions. I’ve found and been told that 4” and smaller timbers don’t need to be boxed heart. As only one dimension is 5", you could get away with not boxing the heart. I'm sure others will give you additional advice on this subject. And I’d be interested in their advice also. Good luck, with your project. Jim
