Second time the block lasted 300 passes with only a minor crack.
in a 10 second drag car thats Only 50 minutes/Less than one hour of actual racing lol & theres no such thing as a minor main Crack lol
heres another ST thread with a builder saying the same thing about the thin walls on the old standard production Cleveland blocks...
Dart Iron Eagle FORD block for Cleveland build? • Speed Talk...
("Your customer's 0.090"-wall Cleveland block is about average for what you're likely to find in the U.S. after 42 years out of production. Depending on what the use is, it may work OK IF you don't bore it at all and limit the hp & rpms- eg, a 450hp-or-so street engine. Add in nitrous or any power adder, run it past 6500 for an extended length of time and the thinner cylinders balloon under compression pressures, ruining ring seal or cracking.")
again, the old p/s racers that were making 700+hp with cleveland blocks in the past were NOT using standard production C blocks...
xe/a3/a4 nascar cleveland blocks were what they were using for high hp...
also, P&S had SD Cleveland block offerings in the past too...