I measured my bare bores and came up with 2.812" (measured several times). Could be a fluke, but anyway, half of that (the radius) is 1.406". The radius of the 440 crank (unturned) is 1.375" The difference is .031", so you can center the 440 in the bare 400 saddles if you put some material (say some kind of flexiable but hard plastic) of .031" thickness between the crank and saddle. Then the crank/block can be clearanced before the mains are turned.

What is a good,but cheap, scale to weight the different parts on?