Unlike the Shelby blocks, all of which require sleeves, a good side oiler block does not. Nor does it require welding anywhere. Mine is neither sleeved or welded on, it's all "natural", right down to it's Le Mans rods and iron heads.
There is no question the Shelby block is stronger than an original side oiler block, OK, and that means...?
There are many that make the same argument for a
center oiler vs a side oiler. Do you really NEED the extra strength of a side oiler? Do you really NEED the priority crankshaft oiling system? Most of us don't, we would do just fine with a center oiler (limiting rpm to 6,500 or less). Want to turn 7,000? Better get the side oiler, more strong. OR, if you plan to run 500 miles at elevated rpm at Daytona Speedway (NASCAR style), or Le Mans, then you will need the side oiler.
We really choose the side oiler because it is legendary. It's association with racing history, for some, a center oiler just won't cut it. Gotta be a side oiler.
Same reasoning applies to the Shelby. It's association with the legend and that extra strength is part of the "new" legend in the making. Not that most of use will plan to run 500 miles at Daytona, or Le Mans, but if we DID, well by golly we could!
So either way, new or old, we choose based on what we can afford, what we want, what makes us happy. The strength issue is really more about bench racing, for most of us, than a real world application, new OR old block!