Look at a KB double bolted block for an idea of what I think would help a stock block live. The double bolt , both top and side, main caps would have to be very large, because the only way to build it would be to build it all below the pan rail. that would create quite a massive add on structure, but if money is not an issue, well, thats' what racers do to win.
The idea is to make the whole deal, main caps and what they are bolted to, so massive that any load put on a single bearing is also transferred to the adjacent two and beyond. That would greatly reduce the stress on the main web area of the cap at the center of the load.