1970 340 Balance Problem...Bottom Line

Also I would like to add that 360s in 1 ton duallys were rumoured to have had forged cranks, but Ive never actually see 1, although 400s with 4 gears had forged cranks, as well as 440s in trucks having forged cranks and 6 pac connecting rods. I do not claim to know everything, but I do know alot of things.......older+wiser kimmer......