Starting late in '69 the 440 HP engines had the forged steel crank and the heavier 6BBL rods. The 6BBL, HP, Magnum and TNT engines were all very similar. The cam grind is the same except that the cam ramping on the 6BBL engine is harder to accommodate the stiffer valve springs. The only way to determine if a 6BBL engine is "real" would be the "M" or "V" code on the outside of the block. The 6BBL engines had some extra finishing done to the crankshaft with a different crank number, #3512036, this engine would also use damper #3512017 which was shared with some of the other externally balanced 440 engines. Quick ID for an externally balanced engine is the HEMI orange color '69-'71, and the egg shaped center section of the harmonic balancer. All 440 engines had steel cranks thru '73, but not all were externally balanced. Later 440's '74 and up used and iron crank that was also externally balanced with the 6BBL style rods.
Dave