273 LA bored .040 change in performance?

Are they all bored .040. We are on our 4th block. all .040 over. 2 low compression 4bbl motors taken from comando cars . I don't get it . My son ordered the correct pistons from EGGE. we started tearing all Todd's 273's down to find a standard bore block. All .040 over
My 273 was standard when I rebuilt it. I went .030+ with the Egge HP pistons to replace the originals. I have no idea why his 273's would all be .040+.