What exactly is the purpose of such an engine, I wonder, in comparison to a stock engine? Sure, 5 mains compared to 3 will benefit the crank, but are broken crankshafts in A's really a common occurrence?
The way I understand it, the stock A's ability to rev higher is limited by (1) the carburetor and (2) the camshaft, perhaps (3) to some degree valve float. So if somebody uses a stock block, a top-notch crankshaft, insert bearings on mains and rods, Venola pistons, ARP bolts, has everything balanced to the T, then adds a "better" carburetor and camshaft, that engine should rev to at least 4,000 rpm, right? Is at that point the 3-main block the limiting factor, or what warrants spending a lot of money on such a block? Just wondering . . .