I am trying to build an F440 HP 4BBL (assembled Trenton MI plant 8/12/69) as close to stock as I can. I have a conflict between sources as to when in the '70 model year Mother Mopar went to externally balanced 440 4BBL's with the six pack rods, balancer and flywheel/converter vs internal balanced.

If you have a 1970 F440 HP 4BBL (U code or E86 Option) with the original unmolested engine let me know the assembly date of your engine and if you have the six pack rods/balancer (eccentric weight)or a neutral balanced balancer.

I walked around the Mopar show at Englishtown this weekend and saw a mixed bag, some internal balanced, some external. The pattern looks like early F440HP's are internal and they didn't go external until the October '69 engine builds.