Pulleys overlapping?

moparmarks said
Maybe but the 440 didn't go cast til mid 73. The 340 did in mid 72. 72-74 400 4-spd had a forged crank.

71 was last year for internal balanced 383 and 72 had the external balanced 340, 360,400s and 6 pac 440s.
I had a 78 400 with a factory forged crank but it was still externally balanced. I think I still have the crank in my garage I think.