If your talking about using a 4.500 stroke crank in a stock 440 block and race it when do you expect that grenade to explode? I wouldn't put that large of a load on the 440 main webs, even with a "girdle" and block filler Remember the designed strength of the B and RB type blocks is in the oil pan rail supports and block skirt, the main webs are not intended or designed to hold much above 700 HP. Sticking a set of main studs and using the oil pan bolts to hold a girdle on the bottom is not my idea of a good design, more like a poor bandiad
Save your money and buy a good block to start with