Turning a 340 crank, How much is to much?

race engines are gone through quite frequently, street engines are not.
sofer bearings have in mind the debris that makes it past the filters and the possibly infrequent oil changes. soft will eat the dirt instead of the journal... other way around with a hard bearing. Im pretty sure those babbit bearings are a lot less forgiving to the journal surface when the misfortune of say the oil film going away.

use hard azz race bearings on the street without changing the oil/filter every 2 weeks month and u'll more than likely have more wear on the journals than if the other way around.jmo

there is a diff between race and street.
If hard babbit bearings were the thing dreams were made of..then all these production engines going 400k have got to be absolute miracles.