273 340 interchange??

All 273-318-340 are same stroke so all the cranks will interchange as a unit, meaning forged crank needs neutral or forged crank balancer, and cast crank needs cast crank balancer, which is weighted, the 273 crank is most likely forged steel and I have used several in 340's that were cast crank motors that I changed to forged, like stated in earlier post , would be advisable to check counterweight and balance, but yes they work and rumor has it that the 273 forged units were better than the 340 ones, that I dont know for sure but I never had an issue with any in my experience. as far as 340 blks other than date codes or yrs they were all the same.