The Magnum blocks are just as good as any LA, and IMO less subject to casting core shift which is what really makes or breaks (pardon the pun) a stock block.
It's not an issue of survival for me. It's more of an issue of cost vs return. Take a core block - then clean it, mag it, sonic test it. If it passes those - then hard block it, fit the caps and studs, if you believe in them fit the girdle, align bore, align hone, clearance for the rods if needed, blueprint cylinder positions, bore, square deck, plate hone, modify the oil system, deburr. Then add in the cash for hard block, the caps, the studs, and the girdle. Total all that up and then look at the cost of a brand new machined block that has ultra thick decks, ultra thick bores, better main thicknesses and 4bolt caps, and a better oiling system. Are the benefits worth the difference in overall costs? Again, just my opinion, but if you're dropping the dollars associated with an engine package making that kind of power a matter of some hundreds more spent on a foundation that will allow the great parts to make maximmum power, and allow for refreshing, rebuilding, or enlargement just makes sense to me.
