Back in 1990 i got a 340 that my dad rebuilt in the late 80s ,put it in my 71 duster and drove it for awhile and one day i took off from a stop light car shifted into 2nd and broke the crank behind #2 rod ,car still ran just had a knock, pulled 340 out and 10 years later put new bearings and crank in it and its in my 69 dart haven't had any problems yet.
then i got a 70 duster for my daughter, had a 70 340 out of a different car put it in her car after restoring her duster drove it 2 miles to get appraised went to start it and BANG, crank broke in same spot ,,behind #2 rod, i don't know why they break there but i've had 2 steel cranks do that. ended up getting another crank for her 340 and been good since
