All three RB blocks(1 426 M.W., two 440) I've seen up until now that cracked the main webs where under #1 and #3 cylinders up towards the cylinder walls I've seen other GM blocks crack the mains like the one pictured here, me thanks that is mainly weakness in the castings and design
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
I've seen other GM blocks crack the mains like the one pictured here, me thanks that is mainly weakness in the castings and design 
