I would not be too concerned with a stock block,properly prepared and depending on it's use.My 4.125 BPE crankshaft is in a stock 360 block and has been being abused for a long time with no issues.
I run mine to 6500 every pass,and used to wind it to 7000.People worry about longevity but how many of us would run something like this for 100,000 miles anyway?
Big block guys run strokes this big or bigger all the time.The lightweight parts that tend to go with the longer strokes really help IMO.
Just my
Keith