Would it be fair to say the Shelby block is superior vs. all other alum blocks?....
Fully redesigned, the Shelby 427 Alloy FE block is 45 percent lighter, yet stronger than the factory cast iron version.
The Shelby block offers these premium performance features:
Deep lifter valley reinforcing webs combined with thick oil pan rails and main webs maximize block strength.
Thick 0.750-inch deck delivers the foundation needed for maximum head gasket sealing and retention.
Priority main oiling system. With the oil gallery raised adjacent to the camshaft bore, oil flow is directed to main bearings first, before going to the cam bearing. Crank life is maximized.
Strong enough to support over 1500 horsepower outputs.
Shelby's FE alloy block delivers superior bottom end stability at high rpm.
This is accomplished by:
Extended skirt design.
2,3,4 main caps are cross bolted with 4 cross bolts. Main caps are billet steel and cap alignment is further enhanced by integral dowel section in the main studs.
Steel caps allow moderate bearing clearances for cold starts.
Centrifugally cast duplicate iron. cylinder sleeves are fitted in the block, with an interference step fit that creates precise, non shift sleeves positioning. Cylinder walls are stained and revised cooling passages make street or race track cooling problems a thing of the past.
The block requires special Shelby head studs, available separately. Unlike a stock block, where the head bolt threads start at the deck surface, the Shelby stud threads are positioned adjacent to the cylinder bore bottom. This configuration delivers maximum gasket seal/retention and minimum cylinder bore distortion when the head is torqued to the block.