At what HP /rpm level are billet main caps and or stud girdle needed?

Over 30 years of running 8.60 - 10.0’s with 440 engines and I never ran one with concrete or girdle on my blocks. The only block I ever found cracks in was a 440source 500 cubic inch combo that made 275 passes running 8.60’s@155mph in my Daytona. That block had 440source steel main caps on it (I’d never do that again). I would never use a stock 440 block again at those power levels. I have a Keith Black block now and sold a mopar mega block last year.