150-250g is in the ballpark.
Many F1 drivers have survived 50g impacts, and an Indy car driver survived a 214g impact, but those last for a couple, maybe tens of milliseconds at most at that peak level. The 737 (or Challenger) impacts were not only as high or higher peak, but lasted a lot longer (hundreds of milliseconds at least, likely 1000-2000 milliseconds). It’s the duration that’s really deadly, more so than the peak. Plus, airline pax aren’t nearly as well restrained, and there’s the whole fireball, and huge amounts of shredded metal going everywhere too.