I now have a Keith Black block but this is how I look at it. It costs me less than 400 dollars to prep a 440 block and that includes cleaning and boring. I install my own cam bearings, block prep, and assembly so that keeps costs down. My first 440's ran hundreds of high 9's-10.40's and only cracked and broke stock forged cranks. When I bought my 2500 pound daytona it ran 9.0's-9.20's for years with zero issues other than cranks showing cranks on 3 year rebuilds. When I built my 440source 500 inch engine it ran 8.60's-8.90's with the only other upgrade being 440source billit main caps. When I tore the engine down for rebuild after 275 (8 second) passes I found that the block was cracked. No water or and other sign of it being cracked. This engine even hit 8500rpm at the line once when it destroyed a set of 4.30 9 inch ford gears. I never have used or will use concrete in one of my engine blocks. I have another 440source 512 cubic inch assembly sitting here that will be running 8's again in my other Duster soon. For the peanuts I spend if I get 250 runs out of a block I will be happy as heck. But being diapers are so cheap now it will probably be wearing one.